Goodwin first had roles in the popular NBC television programs Law & Order and Ed before appearing in the Comedy Central television movie Porn 'n Chicken. She later had substantial roles in the films Mona Lisa Smile, Win a Date with Tad Hamilton!, Walk the Line—in which she portrayed Vivian Liberto, Johnny Cash's first wife—and Birds of America. She also played Dori Dumchovic in the dark comedy Love Comes to the Executioner.[6] Goodwin played a leading role as Margene Heffman, the third wife in a polygamous family, on the HBO original series Big Love, which concluded on ngày 20 tháng 3 năm 2011.

Goodwin starred as Gigi in He's Just Not That into You, which was released in February 2009. For this role she received a nomination for the People's Choice Award for Breakout Movie Actress.[7] In April 2009 she began filming Ramona and Beezus (playing "Aunt Bea").[8]

In 2008, MaxMara honored Goodwin with a "Face of the Future" award, an award recognizing up and coming women in film.[9] Also, Goodwin was one of the celebrities featured in Gap's Fall 2008 ad campaign.[10]

In 2011, Goodwin plays Mary Margaret Blanchard, a teacher in Storybrooke, Maine, as well as fairy tale heroine Snow White, in the revisionist fantasy adventure television program, Once Upon a Time, which debuted on ABC.[11] That same year, she played Rachel in Something Borrowed.