Joan Mary Cusack (; born October 11, 1962) is an American actress. She received Academy Award nominations for Best Supporting Actress for her roles in the romantic comedy-drama Working Girl (1988) and the romantic comedy In & Out (1997), as well as one Golden Globe nomination for her performance in the latter. She is also the voice of Jessie in the Toy Story franchise.

Cusack was a cast member on the comedy sketch show Saturday Night Live from 1985 to 1986. She starred on the Showtime hit drama/comedy Shameless as Sheila Gallagher (née Jackson), a role for which she has received five consecutive Emmy Award nominations, winning for the first time in 2015. She is the sister of actress Ann and actor John Cusack.