Mallory Jansen (born 1989 or 1990) is an Australian actress and model. She is best known for playing Aida / Ophelia / Madame Hydra in the Marvel Cinematic Universe (MCU) television series Agents of S.H.I.E.L.D.

Jansen was born in Australia. In 2011, she moved to New York to train at the Stella Adler Studio of Acting and the T. Schreiber Studio & Theatre.

In 2013, Jansen was cast as Madalena in the ABC series Galavant.

In 2014, Jansen played Helena Christensen in the two-part miniseries INXS: Never Tear Us Apart. She had recurring roles in the ABC Family sitcoms Baby Daddy and Young & Hungry.

Following the cancellation of Galavant, Jansen joined the cast of Agents of S.H.I.E.L.D. in 2016 as Aida, Agnes Kitsworth, the human template of the former, and Madame Hydra.

In 2019, Jansen was cast in the pilot of the ABC drama Triangle alongside Edwin Hodge. In 2020, she was cast in the Fox series The Big Leap, which was canceled after one season.

Jansen moved to Los Angeles in 2013. She is married to Simon Phan.