The round-faced, blondish and slightly chubby Henson had his first substantial film role in 1989's cop/dog buddy film "Turner & Hooch". More memorable was his work as Fulton Reed in Disney's "The Mighty Ducks" (1992), a film co-starring his younger brother Garrette. Noticed after a puck he hits breaks the hockey coach's car window, Fulton has to learn to skate to join the Ducks, and then becomes the team's enforcer and protector. He reprised this role for the popular 1994 and 1996 sequels. Big with the small set, "The Mighty Ducks" trilogy won Henson both fans and recognition, and helped to pave the way for larger roles.
1998 saw the young actor take a co-starring role, playing physically oversized but emotionally underdeveloped Max in "The Mighty", opposite Kieran Culkin's thoughtful and disabled Kevin. Both outcasts, they find each other, with Max helping Kevin overcome his weaknesses by carrying him around on his shoulders while Kevin helps to open up Max's mind with a copy of the tales of King Arthur. Their onscreen friendship was moving, and Henson, giving a sensitive and compelling performance, showed that years of experience in the business had molded him into a fine actor. Singled out by critics for his impressive turn, Henson offered an honest, unaffected and mature portrayal that distinguished him as one to watch among dozens of contemporaries.
Henson re-teamed with Culkin in the teen ensemble comedy "She's All That" (1999), featured as the best friend of Rachael Leigh Cook's character Laney, while Culkin played Laney's younger brother. With the onslaught of teen-themed features came more work for Henson, who could next be seen featured alongside Devon Sawa and Seth Green in "Idle Hands", a 1999 horror-comedy. That same year he lensed the "Othello" update "O" (2001), starring Mekhi Phifer as the lead Odin, and Josh Hartnett as his friend and nemesis Hugo. In addition to acting, Henson has shown an interest in writing and directing, having worked on a number of amateur short films and written several scripts. Henson played one of the canny foursome trying to cheat their way through high school in the 2002 comedy "Cheats" and had a small role in the comedy prequel "Dumb and Dumberer: When Harry Met Lloyd" (2003) before a major appearance in the second "Project Greenlight" feature "The Battle of Shaker Heights" (2003) as Bart, the best friend of Kelly (Shia LaBeouf) who finds their relationsip strained when Kelly's goes after Bart's sister (Amy Smart).