Charlie Day

In the early years of his career, Day often made comedy sketches and absurd short films in his spare time with Jimmi Simpson, whom he was living with in New York City, and several friends including David Hornsby, Nate Mooney, Logan Marshall-Green and other actors, many of whom they had met through the Williamstown Theatre Festival.[14] These home videos served as the inspiration for several scripted short films he later developed with Rob McElhenney and Glenn Howerton in 2003, once he had moved out to LA. Among these home movies were two scenes about three struggling self-involved actors in LA getting into awkward and darkly comedic situations between auditions and jobs,[15] which went on to form the basis of the pilot episode of the comedy series that would go on to be known as It's Always Sunny in Philadelphia.[16]

In 2005, the first season of It's Always Sunny in Philadelphia was released on FX television.[17] In addition to being a co-creator, executive producer and prolific writer on the show, Day plays Charlie Kelly, one of the main characters on the show. His performance received widespread recognition and has been the source of several memes through the years, most notably the Pepe Silvia conspiracy meme.[18] In 2021, Sunny became the longest running live action comedy on American television with the release of its fifteenth season.[19][20] The series is still ongoing with its sixteenth season released in 2023.

Since November 2021, Day, McElhenney and Howerton have been releasing The Always Sunny Podcast. They set out to rewatch the entire series and share behind-the-scenes information, but the podcast's focus shifted to the banter and dynamic between the three creators.[21][22]

Day has also co-created and produced several television shows in addition to It's Always Sunny in Philadelphia. In 2011 and 2012, he produced the short-lived comedies How to Be a Gentleman (2011–2012) and Unsupervised (2012), which were created by Sunny writers David Hornsby, Scott Marder and Rob Rosell. In 2017, he co-created the Fox sitcom The Cool Kids (2018–2019), starring Vicki Lawrence, Martin Mull, David Alan Grier and Leslie Jordan and set in a retirement community.[23] He served as an executive producer through its first season after which the show was canceled.

On August 9, 2019, Mythic Quest (2020–present), a new half-hour comedy series co-created by Day, McElhenney and Megan Ganz, who is also an executive producer on Sunny, was announced as one of the original productions for the then-upcoming streaming service, Apple TV+.[24] In addition to being co-creator, Day is an executive producer on Mythic Quest, which has been renewed for a fourth season.

Day at the premiere for Horrible Bosses in August 2011

In July 2011, Day starred in New Line Cinema's Horrible Bosses with Jason Bateman, Jason Sudeikis, Kevin Spacey, Jennifer Aniston, Colin Farrell, and Jamie Foxx.[3] The film was a commercial success and Day's performance as Dale Arbus was praised by critics. He later reprised the role in the sequel Horrible Bosses 2 released in November 2014. Day had previously worked with Sudeikis in the 2010 film Going the Distance, starring Justin Long and Drew Barrymore.

Day hosted the November 5, 2011, episode of Saturday Night Live (SNL) with Maroon 5 as the musical guest. He was the second cast member from It's Always Sunny in Philadelphia to host SNL (after Danny DeVito, though DeVito hosted SNL before IASIP premiered, the last time being in 1999; notably, however, DeVito would make a brief cameo during Day's opening monologue in this episode). Day would also make another brief cameo in the following season's episode hosted by Jamie Foxx on December 8, 2012, as a congressman in the episode's sketch "Maine Justice".[25] In September 2014, Day provided his voice for The Sims 4 TV spots.

Day had a significant role in the Guillermo del Toro science fiction kaiju film Pacific Rim (2013), in which he played biologist Dr Newton "Newt" Geiszler, who is the focus of the secondary comedic plot with Burn Gorman and Ron Perlman. He was cast based on his performance in the IASIP episode Charlie Kelly: King of the Rats as del Toro was a fan of the show. In exchange, Day created the recurring role of Pappy McPoyle for del Toro on IASIP. In 2018, he reprised the role of Newt for the sequel Pacific Rim Uprising directed by Steven S. DeKnight.[26]

In 2015, Day and Ice Cube were cast as the leads in Fist Fight, a story about two teachers brawling conceived by Max Greenfield.[27] Day plays Andy Campbell, a high school English teacher, who is challenged by his co-worker, history teacher Ronald Strickland (Ice Cube), to a fight after getting him fired.[28] The film was directed by Richie Keen, who had directed episodes of It's Always Sunny in Philadelphia, and released in February 2017.[29][27]

Later that year, Day played Ralph, a vulgar comedian and close friend of the protagonist, in I Love You, Daddy, which was directed by Louis C.K. and featured himself, Chloe Grace Moretz, John Malkovich, Rose Byrne, Pamela Adlon, Edie Falco and Helen Hunt.[30] Day was the first to have been cast as C.K. was a fan of It's Always Sunny in Philadelphia.[31] The film premiered at TIFF 2017 and was scheduled to have its public opening in November 2017, but was dropped by all its distributors after the allegations of C.K.'s sexual misconduct were made public by the New York Times.[32][33] Day had withdrawn himself from the film's promotion and condemned the misconduct in light of the allegations before the film's public release was canceled.[34]

In addition to Pacific Rim Uprising, in 2018, Day was in Drew Pearce's film Hotel Artemis, with Jodie Foster, Sterling K Brown, Sofia Boutella, Jeff Goldblum, Brian Tyree Henry, Jenny Slate, Zachary Quinto and Dave Bautista, where he played Acapulco the arms dealer.[35] Most recently, Day played his first leading role in a romantic comedy as Peter on I Want You Back with Jenny Slate for Amazon Studios released on February 11, 2022.

Day got his first film voice acting role in 2013 as the character Art in the Pixar animated film Monsters University. Following this, he voiced Benny in The Lego Movie (2014) and its sequel The Lego Movie 2: The Second Part (2019). In September 2021, Nintendo announced that Day would voice Luigi, in The Super Mario Bros. Movie, released on April 5, 2023,[36][37] with the potential to reprise the role in a Luigi's Mansion film.[38][39]

In 2018, Day began working on his feature directorial debut Fool's Paradise (previously titled El Tonto), starring Ken Jeong and himself, and featuring Ray Liotta, Kate Beckinsale, Adrien Brody, Common, Jason Sudeikis, Edie Falco and John Malkovich.[40] Besides writing and producing, Day co-stars as a silent man from a psychiatric hospital who accidentally finds his way into celebrity with the help of an enterprising publicist (Jeong) before they lose it all.[41][42] The film underwent several reshoots and was released on May 12, 2023.[43]