In 2006, Dewan co-starred with future husband Channing Tatum in "Step Up" and "Take the Lead".
In 2008, she starred in the Lifetime made-for-television film "Fab Five: The Texas Cheerleader Scandal", as 'Coach Emma Carr'.
In 2009, she appeared in the comedy feature "American Virgin".
In 2011, Dewan portrayed 'Bunny Janie' in "The Playboy Club" TV series.
In 2012 Dewan appeared in the romantic-comedy feature "10 Years", produced by Channing Tatum.
This was followed by an appearance in Season 2 of "American Horror Story" as the character 'Teresa Morrison'.
In 2013, Dewan starred in the Lifetime series "Witches of East End" as 'Freya Beauchamp'.
In 2015 she began a recurring role in the CBS series "Supergirl" playing 'Lucy Lane', the sister of 'Lois Lane' and girlfriend of 'Jimmy Olsen'.