Megan Mullally (born November 12, 1958) is an American actress, comedian, and singer. She is best known for her role as Karen Walker on the NBC sitcom Will & Grace (1998–2006, 2017–present), for which she received eight Primetime Emmy Award nominations for Outstanding Supporting Actress in a Comedy Series, winning twice in 2000 and 2006. She also received nominations for numerous other accolades for her portrayal, including seven consecutive Screen Actors Guild Awards nominations for Outstanding Performance by a Female Actor in a Comedy Series, winning 3 times in 2001, 2002, and 2003, as well as receiving four Golden Globe Award nominations. Since 2017, she has been reprising the role on NBC's revival of the series.

From 2006 to 2007, Mullally hosted The Megan Mullally Show. Since then, she has been a series regular on television series such as In the Motherhood, Party Down, Childrens Hospital, and Breaking In. She has also appeared in guest spots and recurring roles on other comedy series, including Parks and Recreation, Happy Endings, 30 Rock, Up All Night, Boston Legal, and The New Adventures of Old Christine. In addition to television, Mullally has also ventured into film, with appearances in Smashed (2012), The Kings of Summer (2013) and Why Him? (2016).