In 2016, DeWitt appeared in Damien Chazelle's musical romance La La Land opposite Ryan Gosling and Emma Stone.
Other film credits include Jason Reitman's Men, Women, & Children, Michael Cuesta's Kill the Messenger opposite Jeremy Renner, Gus Van Sant's Promised Land opposite Matt Damon, Lynn Shelton's Your Sister's Sister, opposite Emily Blunt and Mark Duplass, and Jonathan Demme's Rachel Getting Married.

DeWitt appeared in the indie-thriller Sweet Virginia, directed by Jamie Dagg, which premiered 2017 at the Tribeca Film Festival.
In 2018, DeWitt starred opposite Danny McBride in Arizona as well as the second episode in the fourth season of the acclaimed British series, “Black Mirror” for director Jodie Foster.

On the small screen, DeWitt was seen in three seasons of the Showtime comedy series, United States of Tara alongside Toni Collette.
In addition to her role on United States of Tara, DeWitt also recurred on the critically acclaimed AMC series, Mad Men, playing Midge Daniels, Don Draper's (Jon Hamm) bohemian mistress in the show's first season.
In 2016, DeWitt appeared in Damien Chazelle's musical romance La La Land opposite Ryan Gosling and Emma Stone. Other film credits include Jason Reitman's Men, Women, & Children, Michael Cuesta's Kill the Messenger opposite Jeremy Renner, Gus Van Sant's Promised Land opposite Matt Damon, Lynn Shelton's Your Sister's Sister, opposite Emily Blunt and Mark Duplass, and Jonathan Demme's Rachel Getting Married. 
DeWitt appeared in the indie-thriller Sweet Virginia, directed by Jamie Dagg, which premiered 2017 at the Tribeca Film Festival. In 2018, DeWitt starred opposite Danny McBride in Arizona as well as the second episode in the fourth season of the acclaimed British series, “Black Mirror” for director Jodie Foster.
On the small screen, DeWitt was seen in three seasons of the Showtime comedy series, United States of Tara alongside Toni Collette. In addition to her role on United States of Tara, DeWitt also recurred on the critically acclaimed AMC series, Mad Men, playing Midge Daniels, Don Draper's (Jon Hamm) bohemian mistress in the show's first season.
Rosemarie DeWitt