Flacco began his football career playing for the University of Delaware Blue Hens. He was then selected by the Baltimore Ravens in the first round of the 2008 NFL Draft. He played for the Ravens for 11 seasons, leading them to a victory in Super Bowl XLVII in 2013. In 2019, Flacco was traded to the Denver Broncos, where he played for one season before signing with the New York Jets in 2020. He joined the Indianapolis Colts in 2021.