Eddie Cahill

In 2000 Cahill performed in Nicky Silver's Off-Broadway production of The Altruists. He was noticed by Sarah Jessica Parker and shortly after he made several television guest-star appearances including Sex and the City, Felicity, and Law & Order: Special Victims Unit. Cahill was also a recurring guest-star in the NBC sitcom Friends as Rachel's young assistant and boyfriend, Tag Jones. In 2002, he starred in a short-lived WB drama, Glory Days.

In the 2004 hockey movie Miracle, Cahill had the chance to play his boyhood hero, goalie Jim Craig. He had never played the goaltender position prior to the movie, so most of the game-action sequences of Craig were filmed with former NHL goalie Bill Ranford doubling for Cahill, although Cahill did shoot several key sequences from within goal.

When CBS decided in 2004 to create a third CSI series, CSI: NY, to add to its franchise, Cahill was hired to play the cocky, snarky homicide detective, Don Flack, who backs up the team of CSIs and who gets some of the best lines. The show ran for nine seasons and he was in all 197 episodes.

Cahill went back to the Atlantic Theater Company in June 2011 and performed at the conclusion of its 25th Anniversary season. He was in Tom Donaghy's one-act play, I Need a Quote, about "a hilarious telephone conversation between a single mother and a home insurance salesman."

In the summer of 2012 Cahill performed in David Adjmi's play, 3C, at the Rattlestick Playwrights Theater in New York City. He played "annoying neighbor Terry, a swinging bachelor true to the era, who unlike everyone else in this play, has no deep feelings at all."

In 2014 Cahill was cast as a main character starting in the second season of the CBS summer drama Under the Dome. He played Sam Verdreaux, a former EMT and reclusive brother-in-law to "Big Jim" Rennie. The series was canceled after three seasons.

Cahill was cast as the male lead in the 2016 ABC legal drama Conviction. He played New York County District Attorney Conner Wallace, who creates the Conviction Integrity Unit, which is set up to re-examine cases where there is a credible suspicion of wrongful conviction. The series was canceled after one season.

In 2019 Cahill played a charismatic criminal in a three-part story arc in CBS's NCIS: New Orleans. Among other crimes he was involved in the death of NCIS Special Agent Christopher Lasalle. In this series, he reunited with his former CSI: NY co-star, Vanessa Ferlito.