Flanagan played with D.C. United's academy until 2016,[1] before spending a year with local club side Baltimore Armour.[2]
College and semi-professional
In 2017, Flanagan attended the University of South Florida to play college soccer. Flanagan went on to make 48 appearances for the Bulls, scoring 4 goals and tallying 7 assists over three seasons. The American Athletic Conference season was cancelled in 2020 due to the COVID-19 pandemic. Flanagan earned First Team All-Conference honors in 2019 and American Athletic Conference All-Academic Team in both 2018 and 2019.[3]
On May 21, 2021, Flanagan was loaned to USL Championship side Orange County SC for the 2021 season.[8] He made his first professional appearance the next day, appearing as an 82nd-minute substitute during a 1–0 win over Sacramento Republic.[9]
Following the 2021 season, Cincinnati declined their contract option on Flanagan.[11] On March 11, 2022, it was announced that Flanagan had signed with FC Cincinnati 2, the club's MLS Next Pro side, ahead of their inaugural season.[12]