Mary Elizabeth Ellis is an American actress. She is best known for her recurring roles as The Waitress on the FX comedy It's Always Sunny in Philadelphia (2005–present), Nick's ex-girlfriend Caroline in the Fox sitcom New Girl (2011–2018), and Lisa Palmer on the Netflix horror-comedy Santa Clarita Diet (2017–2019). She starred as Amy in the shortlived NBC sitcom Perfect Couples (2010–2011) and Debbie Sanderson in the Fox sitcom The Grinder (2015–2016). Most recently, she played Gary's mother Anita in Licorice Pizza (2021), directed by Paul Thomas Anderson.
Since the first season began airing in 2005, Ellis has been mostly known for her role as The Waitress, the object of Charlie Kelly's unrequited infatuation and obsession, on the FX/FXX comedy series It's Always Sunny in Philadelphia (2005–present). Ellis and her It's Always Sunny colleague Artemis Pebdani are members of the Los Angeles-based performance group Discount Cruise to Hell. Together, they wrote and starred in the stage show Mother May I Dance with Mary Jane's Fist?: A Lifetime Original Play at the Upright Citizens Brigade Theater in Los Angeles.
Ellis has also appeared in a number of other television series, including Reno 911!, House M.D., Without a Trace, Cold Case, New Girl, Happy Endings, and Netflix's Santa Clarita Diet and music videos including "Diaper Money" (2013) for The Lonely Island and "Anti-Hero" (2022) for Taylor Swift. Ellis was a series regular on the NBC romantic comedy series Perfect Couples, which ran for one season in 2011. In 2015, she got her first main role as Debbie Sanderson, co-starring with Fred Savage and Rob Lowe in The Grinder. In 2008, she co-wrote and starred as Olive in the independent film A Quiet Little Marriage. In 2020, she appeared in Disney's Godmothered. The next year, she appeared in Licorice Pizza (2021) as Momma Anita.
