Actress Joan Cusack was born on October 11, 1962 in New York City and is the daughter of Nancy (née Carolan) and Dick Cusack. Her father was an advertising executive, writer and actor, and her mother was a mathematics teacher. Her siblings - Susie Cusack, John Cusack, Ann Cusack and Bill Cusack are also actors. Her family is of Irish descent.

Raised in Evanston, Illinois, Cusack was actively encouraged to explore her creativity by her parents, and as a child, she joined the Piven Theater Workshop. She went on to learn and perform improvisation at the Story Theater and The Ark. Later, she attended the University of Wisconsin-Madison, graduating with a bachelor's degree in English. Whilst at university, Cusack took some small film roles, but her big break came after graduation, when she joined the cast of the legendary "Saturday Night Live". However, she only stayed for one season before moving onto explore other projects.

Cusack produced a memorable turn in the acclaimed Broadcast News (1987), and she earned an Oscar nomination for her performance in Working Girl (1988). Other notable films include Addams Family Values (1993), Corrina, Corrina (1994), Grosse Pointe Blank (1997) and In & Out (1997), which earned her a second Oscar nomination. One of her most well-known roles was Rosalie Mullins, the principal of Horace Green Elementary School in School of Rock (2003). She also provided, superbly, the voice of Jessie the Yodeling Cowgirl in Toy Story 2 (1999), Toy Story 3 (2010) and Toy Story 4 (2019). On television, she scored a role on Shameless (2011), with her work garnering her an Emmy nomination.

Joan Cusack is married to an attorney, Dick Burke. They have two sons - Dylan and Miles.