Matt Damon's 5 Most Memorable Roles (Video)

An accomplished actor, Matt Damon has taken on a wide variety of roles both on screen and off over the past two decades.

Most recently, Damon was seen in Steven Soderbergh's sci-fi thriller, Contagion, and will next appear opposite Scarlett Johansson in We Bought a Zoo, out Dec. 23. The philanthropic and environmentally conscious actor will also lend his voice to the animated Happy Feet Two, set for a Nov. 18 release.

In honor of his 41st birthday on Saturday, Oct. 8, The Hollywood Reporter takes a look back on a few of Mr. Damon's most memorable roles.

Good Will Hunting: Damon teamed up with longtime pal Ben Affleck to write and act in the Gus Van Sant directed drama. The duo earned an Academy Award in the best writing category, while Damon nabbed a best actor nomination for his role as the title character. Robin Williams also starred.

The Bourne Film Series: Damon tried his hand -- very successfully -- as an action hero in the Universal trilogy. As Jason Bourne, Damon played a former CIA assassin who suffers from memory loss as he attempts to discover his true identity. The franchise is currently being resurrected with Tony Gilroy at the helm and Jeremy Renner in the starring role.

Invictus: In his second Oscar nominated role, Damon starred opposite Morgan Freeman for the sports biopic Invictus. The Clint Eastwood-helmed project sees Damon as a rugby player who aids Nelson Mandela in his quest to ease racial tensions in apartheid South Africa.

The Ocean's Film Series: In a remake of the 1960 Rat Pack film of the same name, Damon joined George Clooney, Brad Pitt, Casey Affleck, Scott Caan, Don Cheadle Bernie Mac, Elliott Goulde, Andy Garcia and Julia Roberts for Ocean's Eleven. The film was expanded into a trilogy, directed by Stephen Soderbergh.

Political Activist: Damon has been an outspoken supporter of a variety of causes, including humanitarian and environmental efforts. He a co-founder of Water.org and Not On Our Watch, a spokesperson for Feeding America, a supporter of the ONE Campaign and a board member of Toxic Mailstopper -- to name a few. In August, this video went viral in which Damon fiercely defended teachers at the Washington, D.C. Save Our Schools march.

Bonus: I'm F---ing Matt Damon: Though he has been happily married since 2005, Damon made a cameo appearance with Sarah Silverman in this 2009 music clip, in which the two admitted to a faux affair. Silverman's boyfriend at the time, Jimmy Kimmel, responded with his own video titled "I'm F---ing Ben Affleck."