David Alan Hornsby (born December 1, 1975) is an American actor, screenwriter, and producer. He is best known for a recurring role as defrocked priest Matthew "Rickety Cricket" Mara on the FX comedy series It's Always Sunny in Philadelphia (2006-2019), for which he also writes and co-produces. Hornsby also has a regular role on the NBC comedy-crime series Good Girls (2018-2020).
Hornsby was born in Newport News, Virginia, on December 1, 1975. He is a cousin of musician Bruce Hornsby. He grew up in Houston, Texas, and majored in acting at Carnegie Mellon University.
Hornsby plays defrocked priest Matthew "Rickety Cricket" Mara on the FX comedy series It's Always Sunny in Philadelphia, also serving as an executive producer and writer on the show. He appeared as Steve "The Hutch" Hutchinson on The Joe Schmo Show, and as Patrick on Six Feet Under. His first animated role was Fanboy in Fanboy & Chum Chum. He also starred in the independent film Pretty Bird.