Key is perhaps best known as one-half of the comedy duo Key & Peele with Jordan Peele, whom he met while starring on the FOX late-night sketch comedy series Mad TV. Originally, FOX hired Key and Peele so the executives could choose which African-American cast member they wanted. However, Key and Peele ended up both being hired back because of their comedic chemistry and both of them had memorable characters and celebrity impressions. Keegan-Michael Key's most memorable recurring characters include Coach Hines (a quick-tempered Catholic school gym teacher who wears short-shorts and threatens students, including Bobby Lee's character, Yamanashi)note , Jovan Musketelle (a shirtless man with a jheri curl and a shower cap who interrupts live news broadcasts by a reporter — always played by Ike Barinholtz — and annoys him with rapid fire accounts of events that have happened frequently exclaiming "It was crazy as hell!"), and Eugene Struthers (a delivery man who accosts celebrities). His celebrity impressions on MADtv include Keith Richards, Barack Obamanote , Kobe Bryant, Roscoe Ormannote , and even such female celebrities as Phylicia Rashād, Robin Antin, and Eva Longoria (as Gabrielle Solis on a Desperate Housewives parody). Unlike Jordan Peele, Key stayed on MADtv until it ended its run on FOX in 2009.
After MADtv, Key and Peele went to Comedy Central, where they had their own self-titled sketch show that ran from 2012 to 2015. In 2016, Key and Peele starred in the comedy film Keanu, which they also produced.
He is also the biological half-brother of late comic book writer Dwayne McDuffie, with whom he shared a father. Neither Key nor McDuffie were aware of the other's existence in the latter's lifetime, and the former only learned of their relationship after his death.
- Mad TV (2004 — 2009) as himself / various characters
- Reno 911! (2005 — 2008) as Hypothetical Criminal
- Role Models (2008) as Duane
- Childrens Hospital (2010 — 2015) as Cop / Captain Tripper
- Just Go with It (2011) as Ernesto
- Key & Peele (2012 — 2015) as himself / various characters note
- Afternoon Delight (2013) as Bo
- Whose Line Is It Anyway? (2013 — 2016) as himself
- The LEGO Movie (2014) as Frank the Foreman (voice)
- Fargo (2014) as FBI Special Agent Bill Budge
- Parks and Recreation (2014 — 2015) as Joe
- Horrible Bosses 2 (2014) as Mike
- HUNT the TRUTH (2015) as Benjamin Giraud
- Super Mansion (2015 — present) as American Ranger
- Pitch Perfect 2 (2015) as Beca's Boss
- Tomorrowland (2015) as Hugo Gernsback
- Vacation (2015) as Jack Peterson
- Hotel Transylvania 2 (2015) as Murray the Mummy (voice, taking over from Cee-Lo Green)
- Keanu (2016) as Clarence / Smoke Dresden note
- The Angry Birds Movie (2016) as Judge Peckinpah (voice)
- Storks (2016) as Alpha Wolf (voice)
- Why Him? (2016) as Gustav
- Friends from College (2017 — present) as Ethan Turner
- Samurai Jack (2017) as Da Samurai (voice, taking over from David Alan Grier)
- The Predator (2018) as Coyle
- Toy Story 4 (2019) as Ducky (voice)
- The Dark Crystal: Age of Resistance (2019) as skekZok the Ritual-Master (voice)
- Green Eggs and Ham (2019) as Narrator (voice)
Keegan Michael-Key provides examples of the following tropes:
- Alliterative Name: Keegan-Michael Key.
- Bald of Awesome: He has no hair on his head or his face. His baldness falls into the "awesome category" for obvious reasons.
- But Not Too Black: While he considers himself black, he is born to a black father and white mother, and his own chiseled features make this even harder to pin down.
- Keet: Displays a surprising amount of energy for his age, most notably with all his jumping and kicking as Luther. And despite being left to sit out the musical numbers on Whose Line, he's incapable of sitting still.
- Last-Name Basis: He became famous as a member of the "Key & Peele" duo, making him publicly known by his last name. After time has passed, this is no longer the case.
- Large Ham: And massively so.
- No Indoor Voice: While performing, this is something to be expected of him. When being himself, he is noticeably soft-spoken.
- Self-Deprecation: A lot of his roles are comically ridiculous.
- Those Two Guys: With Jordan Peele.