Marrero was named in honor of the Louisiana politician and founder of Marrero Land Company, Louis H. Marrero. The area was originally referred to and shown on maps as "Amesville", after the Boston businessman Oakes Ames, who purchased much of the land following the Civil War. In February 1916, the U.S. Postmaster officially changed the name of the Post Office to "Marrero". Louis Herman Marrero was born in Adams County, Mississippi, on July 17, 1847. When he was a child his family moved to St. Bernard Parish, Louisiana. During his school years at Jackson, Louisiana, the Civil War began, and Marrero joined Captain Scott's Command, later known as the 25th Louisiana Regiment.
As of the census of 2010, there were 33,141 people, 12,218 households, and 8,629 families residing in the CDP. There were 13,212 housing units, of which 994, or 7.5%, were vacant. The human makeup are as follows 49.2% African American, 42.1% White, 0.7% Native American, 4.7% Asian, 0.02% Pacific Islander, 1.7% some other race, and 1.6% from two or more races. Hispanic or Latino of any race were 5.4% of the population. Of the 12,218 households in Marrero, 36.1% had children under the age of 18 living with them, 39.6% were headed by married couples living together, 24.9% had a female householder with no husband present, and 29.4% were non-families. 24.8% of all households were made up of individuals, and 9.9% were someone living alone who was 65 years of age or older. The average household size was 2.69, and the average family size was 3.21. 24.8% of the CDP population was under the age of 18, 9.4% were from 18 to 24, 24.0% from 25 to 44, 27.8% from 45 to 64, and 14.0% were 65 years of age or older. The median age was 38.2 years. For every 100 females, there were 85.8 males. For every 100 females age 18 and over, there were 81.9 males. For the period 2012-16, the estimated median annual income for a household in the CDP was $36,230, and the median income for a family was $48,507. Male full-time workers had a median income of $40,804 versus $31,483 for females. The per capita income for the CDP was $19,643. About 18.6% of families and 23.3% of the population were below the poverty line, including 37.1% of those under age 18 and 18.3% of those age 65 or over.
L.H. Marrero Middle School is in Marrero. Parts of Marrero are zoned to Worley Middle in Westwego, Louisiana and Truman Middle in Marrero. Elementary schools in Marrero include:
Judge Lionel R. Collins Montessori School
* It was previously called Ames Montessori School. In 2011 the school board voted to rename it after an African-American judge who died in 1988. He was the first African-American man elected to a Jefferson Parish-level political office.
Schools outside of Marrero serving portions include Vic A. Pitre Elementary School in Westwego, Estelle Elementary in Estelle. In regards to advanced studies academies, some residents are zoned to the Marrero Academy and some are zoned to the Gretna Academy. The Roman Catholic Archdiocese of New Orleans operates two high schools:
