McCarty attended St. John's College High School where she finished her high school career as the all-time leading scorer in goals and assists. Her 191 goals broke the Washington Metro area scoring record. She led the WCAC Conference in scoring for four straight years while guiding St. Johns to two WCAC Conference Championships. In 2008, she was named a PARADE All-American. She was a three-time NSCAA/adidas High School All-American and a two-time NSCAA/adidas Youth All-American. She was named NSCAA/adidas South Regional All-American and State Player of the Year in the District of Columbia from 2005–2007. She was named Gatorade Player of the Year in the District of Columbia from 2005–2007. McCarty was named a top 25 recruit by Soccer Buzz and was a member of the Maryland state Olympic Development Program squad from 2002–2007. She was also a member of the Region I Regional Team from 2003–2007. McCarty captained the ODP Regional championship team in 2005 and helped the Maryland squad to the 2006 ODP national championship. McCarty also played with the club team, Freestate Shooters. In 2004, she helped the team win the 2004 Maryland state cup championship. In 2007, as captain of the team, she led the team to the 2007 Region I Premier League championship and the 2007 US Club Soccer national championship.
McCarty attended Florida State University where she played for the Seminoles for four years, making 98 appearances, scoring 63 goals and providing 24 assists. She was a semifinalist for the MAC Hermann Trophy in 2009 and 2011.
McCarty was striker for the Washington Freedom of the W-League for three seasons in 2007, 2008 and 2009 capturing the league championship in 2007. She scored a goal in the championship match against the Atlanta Silverbacks and earned W-League Team of the Week Honorable Mention honors in 2009.
On September 25, 2013, Tiffany McCarty was loaned out to Nadeshiko League club Albirex Niigata Ladies in Japan.
Houston Dash, 2014–2015
On January 10, 2014, the Houston Dash selected McCarty with the second pick in the 2014 NWSL Expansion Draft.
FC Kansas City, 2016
On January 13, 2016, McCarty was traded to FC Kansas City along with Jessica McDonald for the 8th overall pick in the 2016 NWSL College Draft. McCarty would chose not to play for FC Kansas City in the 2017 season, opting to play in Norway instead.
Medkila IL, 2017–2018
McCarty signed with Medkila IL in the Toppserien. The Team was relegated following a 12th place finish in the 2017 season.
Washington Spirit, 2018
On August 30, 2018, McCarty was signed as a National TeamReplacement Player by the Washington Spirit for their final game of the 2018 NWSL Season and ended up playing 70 minutes in that September 2 match. McCarty was named to Washington's roster ahead of the 2019 NWSL season.
