In 1993, she performed in her debut movie namely Denys Arcand’s Love and Human remains. Later, in 1996 she got a great opportunity to work for the movie Exotica as a lead actress. Consequently, she established very strongly in her acting profession and gained huge popularity from her role in the Crow: City of Angels. She played the role of the cruelest girl in school in the movie Not another Teen Movie in the year 2001. She made a cameo appearance in the music video Tainted Love.
Mia was ranked in the 43 position on Maxim Hot 100 Women of 2002. Additionally, she has voiced the title character in Bear 71 which was premiered at the Sundance Film Festival. Later she also joined the new Syfy series Defiance.