Morton was nominated two times for a Tony Award for Best Actress in a Play for her performances in August: Osage County and Who's Afraid of Virginia Woolf?.

[3] She has appeared in many stage productions, include Clybourne Park, American Buffalo, Dublin Carol, The Pillowman, Love-Lies-Bleeding and Awake and Sing.

[3] Morton made her Broadway debut as Nurse Ratched, starring opposite Gary Sinise in the Tony Award winning 2001 revival of One Flew Over the Cuckoo's Nest.

She made her feature film debut in a supporting role in 1992 comedy, Straight Talk starring Dolly Parton.

Ten years later, Morton landed her breakthrough role as George Clooney's character's sister in the critically acclaimed drama film Up in the Air directed by Jason Reitman.