In 2007, Reynolds guest-starred as Brendan's friend Hams in the episode "Douchebag in the City" of the TBS sitcom My Boys.
In 2009, he portrayed Andrew Paxton, starring opposite Sandra Bullock, in The Proposal, as well as the possibility of playing the incarnation of The Flash known as Wally West in an adaption of the popular DC Comics character in an upcoming movie project.
Though the film didn't fare well both financially and critically, this role made him one of the few actors to headline in films based on both Marvel and DC characters. (Rest in Peace Department), which was released in 2013.
In 1996, he co-starred with Melissa Joan Hart in the TV movie Sabrina the Teenage Witch.
As an adult, Reynolds starred in the American television series Two Guys, A Girl and a Pizza Place, playing medical student Michael "Berg" Bergen, and in the National Lampoon movie Van Wilder.
Reynolds portrayed Wade Wilson / Weapon XI in a supporting role in the prequel X-Men film, X-Men Origins: Wolverine (2009); a role that he would later reprise in a spin-off feature film based on the character released in 2016.
Reynolds portrayed the Hal Jordan version of superhero Green Lantern in Warner Bros.' film Green Lantern, released on June 17, 2011 in 3D.
In 1993–94 he had a recurring role in The Odyssey as Macro.
Reynolds has also starred in films such as National Lampoon's Van Wilder (2002), The Amityville Horror (2005), Definitely, Maybe (2008), The Proposal (2009), Buried (2010), Mississippi Grind (2015), and Woman in Gold (2015).
Reynolds' career began in 1991, when he starred as Billy Simpson in the Canadian-produced teen soap Hillside, distributed in the United States by Nickelodeon as Fifteen.