Ashford won the 2015 Tony Award for Best Featured Actress in a Play for her performance as Essie Carmichael in the revival of You Can't Take It with You.
In 2017, Ashford starred as Dot/Marie in the critically acclaimed, limited run revival of Sunday in the Park with George opposite Jake Gyllenhaal.
Additionally, Ashford is known for portraying the role of Betty DiMello on the Showtime American period drama television series Masters of Sex, which ran for four seasons on Showtime.
In 2015 she released her debut album, a live album entitled Lost in the Stars: Live at 54 Below.