Glenn Franklin Howerton III (born April 13, 1976) is an American actor of television and film. He is best-known for his role as Dennis Reynolds on FX's It's Always Sunny in Philadelphia on which he is also a writer and executive producer. He also played Corey Howard on the short-lived 2002 sitcom That '80s Show and Ernie Krinklesac on The Cleveland Show.
Glenn provides the voice of Darren in "Weiner of Our Discontent".