She began her television career on the ABC daytime soap operas All My Children as Morgan Gordon, and One Life to Live as Margaret Cochran.

In 2006 she had a small role in The Devil Wears Prada as Jocelyn, the assistant editor whose suggestion for a story about springtime floral prints draws a withering reply from Meryl Streep's Miranda Priestley.

In 2011, she had a recurring role on No Ordinary Family, and in 2012, she made a guest starring appearance on the Fox science-fiction series Fringe as Jessica Holt.

[7] In June 2013, Mader made her stage debut in the role of Barrie in the one-act comedy The Third Date at the Hollywood Fringe Festival.

[11] However, in September 2017, it was announced that Mader would be reprising her role as Zelena in a recurring capacity for the second half of the seventh season.