The 48-year-old star might not be an actor at all if it wasn't for the 1993 classic.
ET spoke with the actor at Clayton and Ellen Kershaw's 6th Annual Ping Pong 4 Purpose event at Dodger Stadium in Los Angeles on Thursday, where he opened up about how the film changed the trajectory of his career.
"That was the role that, at that time I didn't know if it was going to be a hobby or something I was doing for the summer, and it turned out to be a career," he recalled. "That's where it all started and I always look back to that one."
McConaughey starred as David Wooderson in the stoner classic, providing the movie with some of its most iconic scenes and quotable lines. It was one of his first films, and just three years later he scored his big break in 1996's A Time to Kill. He continued to act throughout the late '90s, and earned box office success in the early 2000s with romantic comedies like The Wedding Planner and How to Lose a Guy in 10 Days. In 2014, he won the Academy Award for Best Actor for his performance in Dallas Buyers Club.
Outside of his career, McConaughey is dedicated to helping others with the foundation he shares with his wife, Camila Alves, the Just Keep Livin Foundation. It was that work that he was honored for at Kershaw's Ping Pong 4 Purpose on Thursday.
"Our foundation is doing well, and [having] somebody like Clayton and his group putting the spotlight on us [is great]," McConaughey told ET. "We have a like interest in helping out some kids in need, and he liked what we were doing and finally we partnered up. Now we've got a school that we're both sponsoring working on."
"I think it's such a good partnership between his [organization] and Kershaw's Challenge," Kershaw added. "When we heard about Just Keep Livin and what they're doing, you know, their main target is kids and trying to make kids' lives better and trying to incentivize going to class, incentivize going to school and having these programs to help them achieve that. And it fits perfectly with what we're trying to do at Kershaw's Challenge."
McConaughey may look back fondly at Dazed and Confused, but it's another film he recently told ET takes the cake as one of his all-time favorites. Watch below.