Glenn Franklin Howerton III is an American actor, screenwriter, producer and podcaster. He is best known for playing Dennis Reynolds on the long-running dark satirical comedy It's Always Sunny in Philadelphia (2005–present) on FX/FXX, a series he co-created with Charlie Day and Rob McElhenney, and on which he serves as an executive producer and writer. Since November 2021, he has co-hosted The Always Sunny Podcast, with his fellow co-creators McElhenney and Day.