Although Finn was born in Milwaukee, he was raised for most of his life in Lake Bluff (Illinois) where he attended Lake Forest High School. He later enrolled at Southern Methodist University back in Dallas (Texas) and majored in English. Finn's acting career began in 1999 when he played the role of Corbin Davis in the TV show Sports Night. In total, he has played in nearly 30 TV series and movies combined in his entire career.