[7] Morrison started her career as a child model, appearing in print advertisements for JCPenney and Montgomery Ward, and commercials for Rice Krispies and Mondo.

[8] Morrison made her feature-film debut at the age of 14 in the 1994 film Intersection, and later appeared as Samantha in Stir of Echoes (1999).

[10] She is also one of the producers who found Glee during its early draft and brought it to attention of writer Ryan Murphy, who adapted it into a television series.

[11] In 2007, Morrison appeared as Kirce James in the computer game Command & Conquer 3: Tiberium Wars, a character who frequently interacts with the player during the course of the GDI campaign.

Produced by Lifetime and Working Title Television, Morrison portrays an American journalist who witnesses the car crash in which Diana, Princess of Wales was killed.

In 2009, Morrison returned to the big screen, appearing in the opening scene of J. J. Abrams' Star Trek reboot as James T. Kirk's mother, Winona.

[16][17][18] In 2011, Morrison appeared in Warrior, a film about two estranged brothers who enter a mixed martial arts tournament and are forced to confront their struggling relationship with each other and with their father.

She played the role of Emma Swan, a bail-bonds collector who turns out to be the daughter of Snow White and Prince Charming.

[28] In 2017, she made her feature film directorial debut with Sun Dogs, starring Michael Angarano, Melissa Benoist, and Allison Janney.

[29] In June 2019, Morrison was confirmed to join the cast of This Is Us in a recurring role for the fourth season as Cassidy Sharp, an alcoholic and Marine veteran grappling with her return to civilian life.