List of law enforcement agencies in Illinois

State agencies

• Illinois Attorney General's Office
• * Department of Investigations
• * Illinois Attorney General Police
• Illinois Commerce Commission Police
• Illinois Department of Corrections
• Illinois Department of Human Services Police Department
• Illinois Department of Natural Resources
• * Illinois Conservation Police
• Illinois Department of Revenue Police
• * Bureau of Criminal Investigations
• Illinois Gaming Board
• Illinois Secretary of State
• *Illinois Secretary of State Capitol Police
• * Illinois Secretary of State Police
• Illinois State Fire Marshal Arson Investigation
• Illinois State Police

  County agencies

Sheriff's departments/offices

• Adams County Sheriff's Office
• Alexander County Sheriff's Office
• Bond County Sheriff's Office
• Boone County Sheriff's Office
• Brown County Sheriff's Office
• Bureau County Sheriff's Office
• Calhoun County Sheriff's Office
• Carroll County Sheriff's Office
• Cass County Sheriff's Office
• Champaign County Sheriff's Office
• Christian County Sheriff's Office
• Clark County Sheriff's Office
• Clay County Sheriff's Office
• Clinton County Sheriff's Office
• Coles County Sheriff's Office
• Cook County Sheriff's Office
• Crawford County Sheriff's Office
• Cumberland County Sheriff's Office
• DeKalb County Sheriff's Office
• Dewitt County Sheriff's Office
• Douglas County Sheriff's Office
• DuPage County Sheriff's Office
• Edgar County Sheriff's Office
• Edwards County Sheriff's Office
• Effingham County Sheriff's Office
• Fayette County Sheriff's Office
• Ford County Sheriff's Office
• Franklin County Sheriff's Office
• Fulton County Sheriff's Office
• Gallatin County Sheriff's Office
• Greene County Sheriff's Office
• Grundy County Sheriff's Office
• Hamilton County Sheriff's Office
• Hancock County Sheriff's Office
• Hardin County Sheriff's Office
• Henderson County Sheriff's Office
• Henry County Sheriff's Office
• Iroquois County Sheriff's Office
• Jackson County Sheriff's Office
• Jasper County Sheriff's Office
• Jefferson County Sheriff's Office
• Jersey County Sheriff's Office
• Jo Daviess County Sheriff's Office
• Johnson County Sheriff's Office
• Kane County Sheriff's Office
• Kankakee County Sheriff's Office
• Kendall County Sheriff's Office
• Knox County Sheriff's Office
• LaSalle County Sheriff's Office
• Lake County Sheriff's Office
• Lawrence County Sheriff's Office
• Lee County Sheriff's Office
• Livingston County Sheriff's Office
• Logan County Sheriff's Office
• Macon County Sheriff's Office
• Macoupin County Sheriff's Office
• Madison County Sheriff's Office
• Marion County Sheriff's Office
• Marshall County Sheriff's Office
• Mason County Sheriff's Office
• Massac County Sheriff's Office
• Mc Donough County Sheriff's Office
• Mc Henry County Sheriff's Department
• Mc Lean County Sheriff's Office
• Menard County Sheriff's Office
• Mercer County Sheriff's Office
• Monroe County Sheriff's Office
• Montgomery County Sheriff's Office
• Morgan County Sheriff's Office
• Moultrie County Sheriff's Office
• Ogle County Sheriff's Office
• Peoria County Sheriff's Office
• Perry County Sheriff's Office
• Piatt County Sheriff's Office
• Pike County Sheriff's Office
• Pope County Sheriff's Office
• Pulaski County Sheriff's Office
• Putnam County Sheriff's Office
• Randolph County Sheriff's Office
• Richland County Sheriff's Office
• Rock Island County Sheriff's Office
• Saint Clair County Sheriff's Office
• Saline County Sheriff's Office
• Sangamon County Sheriff's Office
• Schuyler County Sheriff's Office
• Scott County Sheriff's Office
• Shelby County Sheriff's Office
• Stark County Sheriff's Office
• Stephenson County Sheriff's Office
• Tazewell County Sheriff's Office
• Union County Sheriff's Office
• Vermilion County Sheriff's Office
• Wabash County Sheriff's Office
• Warren County Sheriff's Office
• Washington County Sheriff's Office
• Wayne County Sheriff's Office
• White County Sheriff's Office
• Whiteside County Sheriff's Office
• Will County Sheriff's Office
• Williamson County Sheriff's Office
• Winnebago County Sheriff's Office
• Woodford County Sheriff's Office

  County Forest Preserve police departments

• Forest Preserve District of Cook County, Department of Law Enforcement
• Forest Preserve District of DuPage County, Law Enforcement Department
• Forest Preserve District of Kane County, Public Safety Department
• Lake County Forest Preserves, Public Safety Department, aka Ranger Police Department
• Forest Preserve District of Will County, Police Department

  Other county departments

• Cook County State's Attorneys Office, Investigations Unit
• Cook County Hospital Police Department established in 1975, all police officers at this agency are sworn and have graduated from a accredited Police Training Academy.
• McHenry County Conservation Police Department
• Oak Forest Hospital Department of Public Safety
• Vermilion County Conservation Police Department

  Municipal agencies

• Abingdon Police Department
• Addison Police Department
• Albany Police Department
• Albers Police Department
• Albion Police Department
• Aledo Police Department
• Alexis Police Department
• Algonquin Police Department
• Alma Police Department
• Alorton Police Department
• Alpha Police Department
• Alsip Police Department
• Altamont Police Department
• Alton Police Department
• Altona Police Department
• Alvin Police Department
• Amboy Police Department
• Andalusia Police Department
• Anna Police Department
• Annawan Police Department
• Antioch Police Department
• Apple River Police Department
• Arcola Police Department
• Argenta Police Department
• Arlington Heights Police Department
• Aroma Park Police Department
• Arthur Police Department
• Ashkum Police Department
• Ashland Police Department
• Ashley Police Department
• Ashton Police Department
• Assumption Police Department
• Astoria Police Department
• Athens Police Department
• Atkinson Police Department
• Atlanta Police Department
• Atwood Police Department
• Auburn Police Department
• Augusta Police Department
• Aurora Police Department
• Ava Police Department
• Aviston Police Department
• Avon Police Department
• Baldwin Police Department
• Bannockburn Police Department
• Barrington Police Department
• Barrington Hills Police Department
• Barrington-Inverness Police Department
• Barry Police Department
• Bartlett Police Department
• Bartonville Police Department
• Batavia Police Department
• Bath Police Department
• Baylis Police Department
• Bayview Gardens Police Department
• Beardstown Police Department
• Beckemeyer Police Department
• Bedford Park Police Department
• Beecher Police Department
• Belgium Police Department
• Belleville Police Department
• Bellflower Police Department
• Bellwood Police Department
• Belvidere Police Department
• Bement Police Department
• Benld Police Department
• Bensenville Police Department
• Benton Police Department
• Berkeley Police Department
• Berwyn Police Department
• Bethalto Police Department
• Bethany Police Department
• Blandinsville Police Department
• Bloomingdale Police Department
• Bloomington Police Department
• Blue Island Police Department
• Blue Mound Police Department
• Bluffs Police Department
• Bolingbrook Police Department
• Bonnie Police Department
• Bourbonnais Police Department
• Bradford Police Department
• Bradley Police Department
• Braidwood Police Department
• Breese Police Department
• Bridgeport Police Department
• Bridgeview Police Department
• Brighton Police Department
• Broadview Police Department
• Brocton Police Department
• Brookfield Police Department
• Brooklyn Police Department
• Brookport Police Department
• Brownstown Police Department
• Buckner Police Department
• Buda Police Department
• Buffalo Grove Police Department
• Buffalo-Mechanicsburg Police Department
• Bull Valley Police Department
• Buncombe Police Department
• Bunker Hill Police Department
• Burbank Police Department
• Bureau Police Department
• Burnham Police Department
• Burr Ridge Police Department
• Bushnell Police Department
• Byron Police Department
• Cahokia Police Department
• Cairo Police Department
• Calumet City Police Department
• Calumet Park Police Department
• Cambria Police Department
• Camp Point Police Department
• Campton Hills Police Department
• Canton Police Department
• Carbondale Police Department
• Carlinville Police Department
• Carlyle Police Department
• Carmi Police Department
• Carol Stream Police Department
• Carpentersville Police Department
• Carrier Mills Police Department
• Carrollton Police Department
• Carterville Police Department
• Carthage Police Department
• Cary Police Department
• Casey Police Department
• Caseyville Police Department
• Catlin Police Department
• Cave-In-Park Police Department
• Cedar Point Police Department
• Cedarville Police Department
• Central City Police Department
• Centralia Police Department
• Centreville Police Department
• Cerro Gordo Police Department
• Chadwick Police Department
• Champaign Police Department
• Chandlerville Police Department
• Channahon Police Department
• Chapin Police Department
• Charleston Police Department
• Chatham Police Department
• Chebanse Police Department
• Chenoa Police Department
• Cherry Police Department
• Cherry Valley Police Department
• Chester Police Department
• Chesterfield Police Department
• Chicago Heights Police Department
• Chicago Police Department
• Chicago Ridge Police Department
• Chillicothe Police Department
• Chrisman Police Department
• Christopher Police Department
• Cicero Police Department
• Cissna Park Police Department
• Clarendon Hills Police Department
• Clayton Police Department
• Clinton Police Department
• Coal City Police Department
• Coal Valley Police Department
• Cobden Police Department
• Coffeen Police Department
• Colchester Police Department
• Colfax Police Department
• Collinsville Police Department
• Colona Police Department
• Columbia Police Department
• Cordova Police Department
• Cortland Police Department
• Coulterville Police Department
• Country Club Hills Police Department
• Countryside Police Department
• Cowden Police Department
• Crainsville Police Department
• Creal Springs Police Department
• Crest Hill Police Department
• Crestwood Police Department
• Crete Police Department
• Creve Coeur Police Department
• Crossville Police Department
• Crystal Lake Police Department
• Cuba Police Department
• Cutler Police Department
• Cypress Police Department
• Dallas City Police Department
• Dalzell Police Department
• Dana Police Department
• Danvers Police Department
• Danville Police Department
• Darien Police Department
• De Pue Police Department
• Decatur Police Department
• Deer Creek-Goodfield Police Department
• Deerfield Police Department
• Dekalb Police Department
• Delavan Police Department
• DePue Police Department
• Des Plaines Police Department
• DeSoto Police Department
• Divernon Police Department
• Dixmoor Police Department
• Dixon Police Department
• Dolton Police Department
• Dongola Police Department
• Donnellson Police Department
• Dowell Police Department
• Downers Grove Police Department
• Downs Police Department
• Du Quoin Police Department
• Dunfermline Police Department
• Dupo Police Department
• Durand Police Department
• Dwight Police Department
• Earlville Police Department
• East Alton Police Department
• East Carondelet Police Department
• East Dubuque Police Department
• East Dundee Police Department
• East Galesburg Police Department
• East Hazel Crest Police Department
• East Moline Police Department
• East Peoria Police Department
• East St Louis Police Department
• Easton Police Department
• Edinburg Police Department
• Edwardsville Police Department
• Effingham Police Department
• El Paso Police Department
• Elburn Police Department
• Eldorado Police Department
• Elgin Police Department
• Elizabeth Police Department
• Elk Grove Village Police Department
• Elkhart Police Department
• Elkville Police Department
• Ellis Grove Police Department
• Elmhurst Police Department
• Elmwood Police Department
• Elmwood Park Police Department
• Elsah Police Department
• Elwood Police Department
• Emden Police Department
• Energy Police Department
• Enfield Police Department
• Erie Police Department
• Eureka Police Department
• Evanston Police Department
• Evansville Police Department
• Evergreen Park Police Department
• Ewing Police Department
• Fairbury Police Department
• Fairfield Police Department
• Fairmont City Police Department
• Fairmount Police Department
• Fairview Heights Police Department
• Fairview Police Department
• Farina Police Department
• Farmer City Police Department
• Farmington Police Department
• Fayetteville Police Department
• Fillmore Police Department
• Findlay Police Department
• Fisher Police Department
• Fithian Police Department
• Flora Police Department
• Flossmoor Police Department
• Forest City Police Department
• Forest Park Police Department
• Forest View Police Department
• Fox Lake Police Department
• Fox River Grove Police Department
• Frankfort Police Department
• Franklin Grove Police Department
• Franklin Park Police Department
• Freeburg Police Department
• Freeport Police Department
• Fulton Police Department
• Galatia Police Department
• Galena Police Department
• Galesburg Police Department
• Galva Police Department
• Gardner Police Department
• Geneseo Police Department
• Geneva Police Department
• Genoa Police Department
• Georgetown Police Department
• German Valley Police Department
• Gibson City Police Department
• Gillespie Police Department
• Gilman Police Department
• Girard Police Department
• Glasford Police Department
• Glen Carbon Police Department
• Glen Ellyn Police Department
• Glencoe Department of Public Safety
• Glendale Heights Police Department
• Glenview Police Department
• Glenwood Police Department
• Golconda Police Department
• Golf Police Department
• Goreville Police Department
• Grafton Police Department
• Grandview Police Department
• Granite City Police Department
• Granville Police Department
• Grant Park Police Department
• Grayslake Police Department
• Grayville Police Department
• Great Lakes Police Department
• Green Valley Police Department
• Greenfield Police Department
• Greenup Police Department
• Greenview Police Department
• Greenville Police Department
• Gridley Police Department
• Griggsville Police Department
• Gurnee Police Department
• Hamel Police Department
• Hamilton Police Department
• Hampshire Police Department
• Hampton Police Department
• Hanover Park Police Department
• Hanover Police Department
• Hardin Police Department
• Harrisburg Police Department
• Hartford Police Department
• Harvard Police Department
• Harvel Police Department
• Harvey Police Department
• Harwood Heights Police Department
• Havana Police Department
• Hawthorn Woods Police Department
• Hazel Crest Police Department
• Hebron Police Department
• Hennepin Police Department
• Henry Police Department
• Herrin Police Department
• Herscher Police Department
• Heyworth Police Department
• Hickory Hills Police Department
• Highland Park Police Department
• Highland Police Department
• Highwood Police Department
• Hillcrest Police Department
• Hillsboro Police Department
• Hillside Police Department
• Hinckley Police Department
• Hinsdale Police Department
• Hodgkins Police Department
• Hoffman Estates Police Department
• Hometown Police Department
• Homewood Police Department
• Hoopeston Police Department
• Hopedale Police Department
• Hudson Police Department
• Huntley Police Department
• Hurst Police Department
• Illiopolis Police Department
• India Head Park Police Department
• Island Lake Police Department
• Itasca Police Department
• Jacksonville Police Department
• Jerome Police Department
• Jerseyville Police Department
• Johnsburg Police Department
• Johnston City Police Department
• Joliet Police Department
• Jonesboro Police Department
• Justice Police Department
• Kankakee Police Department
• Kansas Police Department
• Karnak Police Department
• Keithsburg Police Department
• Kenilworth Police Department
• Kewanee Police Department
• Kildeer Police Department
• Kincaid Police Department
• Kingston Police Department
• Kinmundy Police Department
• Kirkland Police Department
• Knoxville Police Department
• La Grange Park Police Department
• La Grange Police Department
• La Harpe Police Department
• La Salle Police Department
• Lacon Police Department
• Ladd Police Department
• Lake Bluff Police Department
• Lake Forest Police Department
• Lake in the Hills Police Department
• Lake Zurich Police Department
• Lakemoor Police Department
• LaMoille Police Department
• Lanark Police Department
• Lansing Police Department
• Lawrenceville Police Department
• Lebanon Police Department
• Leland Police Department
• Lemont Police Department
• Lena Police Department
• Lenzburg Police Department
• LeRoy Police Department
• Lewistown Police Department
• Lexington Police Department
• Libertyville Police Department
• Lincoln Police Department
• Lincolnshire Police Department
• Lincolnwood Police Department
• Lindenhurst Police Department
• Lisle Police Department
• Litchfield Police Department
• Livingston Police Department
• Lockport Police Department
• Lombard Police Department
• Loves Park Police Department
• Lovington Police Department
• Ludlow Police Department
• Lyndon Police Department
• Lyons Police Department
• Mackinaw Police Department
• Macomb Police Department
• Madison Police Department
• Mahomet Police Department
• Malta Police Department
• Manhattan Police Department
• Manito Police Department
• Mansfield Police Department
• Manteno Police Department
• Marengo Police Department
• Marion Police Department
• Marissa Police Department
• Markham Police Department
• Maroa Police Department
• Marseilles Police Department
• Marshall Police Department
• Martinsville Police Department
• Maryville Police Department
• Mascoutah Police Department
• Mason City Police Department
• Matteson Police Department
• Mattoon Police Department
• Maywood Police Department
• McCook Police Department
• McCullom Lake Police Department
• McHenry Police Department
• McLeansboro Police Department
• Melrose Park Police Department
• Mendota Police Department
• Meredosia Police Department
• Merrionette Park Police Department
• Metamora Police Department
• Metropolis Police Department
• Midlothian Police Department
• Milan Police Department
• Milford Police Department
• Milledgeville Police Department
• Millstadt Police Department
• Minier-Armington Police Department
• Minonk Police Department
• Minooka Police Department
• Mokena Police Department
• Moline Police Department
• Momence Police Department
• Monee Police Department
• Montgomery Police Department
• Monticello Police Department
• Morris Police Department
• Morrison Police Department
• Morrisonville Police Department
• Morton Grove Police Department
• Morton Police Department
• Mound City Police Department
• Mounds Police Department
• Mount Carmel Police Department
• Mount Carroll Police Department
• Mount Morris Police Department
• Mount Olive Police Department
• Mount Prospect Police Department
• Mount Pulaski Police Department
• Mount Sterling Police Department
• Mount Vernon Police Department
• Mount Zion Police Department
• Moweaqua Police Department
• Mundelein Police Department
• Murphysboro Police Department
• Naperville Police Department
• Nashville Police Department
• Nauvoo Police Department
• Neoga Police Department
• Neponset Police Department
• New Athens Police Department
• New Baden Police Department
• New Berlin Police Department
• New Lenox Police Department
• Newman Police Department
• Newton Police Department
• Niles Police Department
• Nokomis Police Department
• Normal Police Department
• Norridge Police Department
• Norris City Police Department
• North Aurora Police Department
• North Chicago Police Department
• North Pekin Police Department
• North Riverside Police Department
• Northbrook Police Department
• Northfield Police Department
• Northlake Police Department
• Oak Brook Police Department
• Oak Forest Police Department
• Oak Lawn Police Department
• Oak Park Police Department
• Oakbrook Terrace Police Department
• Oakland Police Department
• Oakwood Hills Police Department
• Oakwood Police Department
• Oblong Police Department
• Odin Police Department
• O'Fallon Police Department
• Oglesby Police Department
• Okawville Police Department
• Olney Police Department
• Olympia Fields Police Department
• Onarga Police Department
• Oquawka Police Department
• Oregon Police Department
• Orland Hills Police Department
• Orland Park Police Department
• Oswego Police Department
• Ottawa Police Department
• Palatine Police Department
• Palestine Police Department
• Palos Heights Police Department
• Palos Hills Police Department
• Palos Park Police Department
• Pana Police Department
• Paris Police Department
• Park City Police Department
• Park Forest Police Department
• Park Ridge Police Department
• Patoka Police Department
• Pawnee Police Department
• Paxton Police Department
• Payson Police Department
• Pearl City Police Department
• Pecatonica Police Department
• Pekin Police Department
• Peoria Heights Police Department
• Peoria Police Department
• Peotone Police Department
• Peru Police Department
• Petersburg Police Department
• Phoenix Police Department
• Pinckneyville Police Department
• Pingree Grove Police Department
• Piper City Police Department
• Pittsfield Police Department
• Plainfield Police Department
• Plano Police Department
• Pleasant Hill Police Department
• Pleasant Plains Police Department
• Polo Police Department
• Pontiac Police Department
• Pontoon Beach Police Department
• Port Byron Police Department
• Posen Police Department
• Prairie Grove Police Department
• Princeton Police Department
• Prophetstown Police Department
• Prospect Heights Police Department
• Quincy Police Department
• Rantoul Police Department
• Raymond Police Department
• Red Bud Police Department
• Richmond Police Department
• Richton Park Police Department
• Ridge Farm Police Department
• Ridgway Police Department
• River Forest Police Department
• River Grove Police Department
• Riverdale Police Department
• Riverside Police Department
• Riverton Police Department
• Riverwoods Police Department
• Robbins Police Department
• Robinson Police Department
• Rochelle Police Department
• Rochester Police Department
• Rock Falls Police Department
• Rock Island Police Department
• Rockford Police Department
• Rockton Police Department
• Rolling Meadows Police Department
• Romeoville Police Department
• Roodhouse Police Department
• Roscoe Police Department
• Roselle Police Department
• Rosemont Police Department
• Rosiclare Police Department
• Rossville Police Department
• Round Lake Beach Police Department
• Round Lake Heights Police Department
• Round Lake Park-Hainesville Police Department
• Round Lake Police Department
• Roxana Police Department
• Royal Lakes Police Department
• Royalton Police Department
• Rushville Police Department
• Salem Police Department
• San Jose Police Department
• Sandoval Police Department
• Sandwich Police Department
• Sauget Police Department
• Sauk Village Police Department
• Savanna Police Department
• Schaumburg Police Department
• Schiller Park Police Department
• Seneca Police Department
• Sesser Police Department
• Shannon Police Department
• Shawneetown Police Department
• Sheffield Police Department
• Shelbyville Police Department
• Sherman Police Department
• Sherrard Police Department
• Shiloh Police Department
• Shipman Police Department
• Shorewood Police Department
• Silvis Police Department
• Skokie Police Department
• Sleepy Hollow Police Department
• Smithton Police Department
• Somonauk Police Department
• South Beloit Police Department
• South Elgin Police Department
• South Holland Police Department
• South Jacksonville Police Department
• South Roxana Police Department
• Sparta Police Department
• Spring Valley Police Department
• Springfield Police Department
• St Charles Police Department
• St Elmo Police Department
• St Peter Police Department
• Staunton Police Department
• Steeleville Police Department
• Steger Police Department
• Sterling Police Department
• Stickney Police Department
• Stockton Police Department
• Stone Park Police Department
• Streamwood Police Department
• Streator Police Department
• Sugar Grove Police Department
• Sullivan Police Department
• Summerfield Police Department
• Summit Police Department
• Sumner Police Department
• Swansea Police Department
• Sycamore Police Department
• Tampico Police Department
• Taylorville Police Department
• Teutopolis Police Department
• Thomasboro Police Department
• Thomson Police Department
• Thornton Police Department
• Tilton Police Department
• Tinley Park Police Department
• Tiskilwa Police Department
• Toledo Police Department
• Tolono Police Department
• Toluca Police Department
• Toulon Police Department
• Tower Lakes Police Department
• Tremont Police Department
• Trenton Police Department
• Troy Police Department
• Tuscola Police Department
• Ullin Police Department
• University Park Police Department
• Urbana Police Department
• Utica Police Department
• Valmeyer Police Department
• Vandalia Police Department
• Venice Police Department
• Vernon Hills Police Department
• Vienna Police Department
• Villa Grove Police Department
• Villa Park Police Department
• Viola Police Department
• Virden Police Department
• Virginia Police Department
• Walnut Police Department
• Warren Police Department
• Warrensburg Police Department
• Warrenville Police Department
• Washburn Police Department
• Washington Park Police Department
• Washington Police Department
• Waterloo Police Department
• Waterman Police Department
• Watseka Police Department
• Wauconda Police Department
• Waukegan Police Department
• Waverly Police Department
• Wayne Police Department
• Wenona Police Department
• West Chicago Police Department
• West Dundee Police Department
• West Frankfort Police Department
• West Salem Police Department
• Westchester Police Department
• Western Springs Police Department
• Westfield Police Department
• Westmont Police Department
• Westville Police Department
• Wheaton Police Department
• Wheeling Police Department
• White Hall Police Department
• Williamson Police Department
• Willow Springs Police Department
• Willowbrook Police Department
• Wilmette Police Department
• Wilmington Police Department
• Wilsonville Police Department
• Windsor Police Department
• Winfield Police Department
• Winnebago Police Department
• Winnetka Police Department
• Winthrop Harbor Police Department
• Witt Police Department
• Wood Dale Police Department
• Wood River Police Department
• Woodhull Police Department
• Woodridge Police Department
• Woodstock Police Department
• Worden Police Department
• Worth Police Department
• Wyanet Police Department
• Wyoming Police Department
• Xenia Police Department
• Yorkville Police Department
• Zeigler Police Department
• Zion Police Department

  Special district agencies

Park district police agencies

• Calumet Memorial Park Police Department
• Canton Park District Police Department
• Crystal Lake Park District Police Department
• Decatur Park District Police Department
• East St Louis Park District Police Department
• Fondulac Park District Police Department
• Fox Valley Park District Police Department
• Hawthorne Park District Police Department
• Lockport Township Park District Police Department
• Morton Grove Park District Police Department
• Naperville Park District Police Department
• Pekin Park District Police Department
• Peoria Park District Police Department
• Rockford Park District Police Department
• Round Lake Area Park District Police Department
• Springfield Park District Police Department
• Zion Park District Police Department

  Other special district agencies

• Abraham Lincoln Capital Airport Police Department
• Chicago Zoological Society Police Department
• Effingham Water Authority Police Department
• Metra Police Department
• Metropolitan Airport Authority of Rock Island County Public Safety
• Metropolitan Water Reclamation District of Greater Chicago Police Department
• Northern Indiana Commuter Transportation District Police

  College and university agencies

• Aurora University Campus Public Safety Department
• Augustana College Police Department
• Benedictine University Police Department Lisle Campus
• Benedictine University Police Department Springfield Campus
• Bradley University Police Department
• Chicago State University Police Department
• Eastern Illinois University Police Department
• Eureka College Police Department
• Governors State University Police Department
• Illinois State University Police Department
• Lewis University Police Department
• Loyola University Chicago Department of Campus Safety
• McKendree University Public Safety
• Millikin University Campus Police Department
• Moody Bible Institute Department of Public Safety
• North Central College Department of Public Safety
• Northeastern Illinois University Police Department
• Northern Illinois University Police Department
• Northwestern University Police Department
• Rockford University Department of Police and Public Safety
• Saint Xavier University Department of Public Safety
• Southern Illinois University Carbondale Police Department
• Southern Illinois University Edwardsville Police Department
• Southern Illinois University School of Medicine Office of Police and Security
• University of Chicago Police Department
• University of Illinois at Chicago Police Department
• University of Illinois at Springfield Police Department
• University of Illinois at Urbana-Champaign Police Department
• Western Illinois University - Office of Public Safety

  Community or junior college agencies

• Black Hawk College Police Department
• City College of Chicago Office of Public Safety
• College of DuPage Police Department
• College of Lake County Police Department
• Elgin Community College Police Department
• Harper College Police Department
• Illinois Central College Campus Police Department
• John A. Logan College Police Department
• John Wood Community College Police Department
• Joliet Junior College Police Department
• Kankakee Community College Police Department
• Lake Land College Police Department
• Lincoln Land Community College Police Department
• McHenry County College Police Department
• Moraine Valley Community College Police Department
• Morton College Police Department
• Oakton Community College Police Department
• Parkland College Police Department
• Rend Lake College Police Department
• Rock Valley College Police Department
• South Suburban College Police Department
• Southwestern Illinois College Police Department
• Triton College Police Department
• Waubonsee Community College Police Department

  Railroad police departments

• AG Valley Railroad Police Department
• Alton & Southern Railway Police Department
• Amtrak Police Department
• Belt Railway Police Department
• Burlington Northern/Santa Fe Railroad Police Department
• Canadian National Railway Police
• Canadian Pacific Railway Police Service
• CSX Transportation Police Department
• I & M Rail Link LLC Police Department
• Norfolk Southern Railway Police Department
• Terminal Railroad Police Department
• Union Pacific Railroad Police Department

  Defunct agencies

• Chicago Department of Aviation Police Department
• Chicago Housing Authority Police Department
• Chicago Park District Police Department
• Chicago Transit Authority Police Department
• Clyde Park District Police Department
• Dixmoor Park District Police Department
• Ford Heights Police Department
• Forest Park Park District Police Department
• Illinois Department of Central Management Services Police
• Illinois Department of Mental Health Police
• London Mills Police Department
• Maywood Park District Police Department
• Memorial Park District Police Department
• Peoria Public Schools Campus Police Department
• Markham Park District Police Department
• East Chicago Heights Police Department was renamed Ford Heights Police Department before being disbanded as stated above.
• The Park Forest South Police Department changed their name to University Park Police Department.
• Thornton Community College Police Department is currently named South Suburban Community College Police Department.