Rob McElhenney is an American actor, writer and producer best known for his leading role as Mac on the television comedy series It's Always Sunny in Philadelphia (which he co-created, wrote and produces), since 2005.
McElhenney has also been featured in Lost on ABC. He has appeared on NBC's ER and Law & Order and had a recurring role on ABC's All My Children.
McElhenney made his film debut in Sony's The Devil's Own, starring Harrison Ford and Brad Pitt. He followed that up with Paramount's A Civil Action, starring John Travolta and Wonder Boys, starring Michael Douglas.
Other film credits include Sony's Thirteen Conversations About One Thing and the dramas Tollbooth and Latter Days.
McElhenney was born in Philadelphia and wrote Sunny as the ultimate homage to his hometown. He lives in Los Angeles with his wife Kaitlin Olson, who plays Dee Reynolds in Sunny.