Millie Wynn was born on March 29, 1984 at Yale Hospital in New Haven, Connecticut. Her father was an engineer. Her mother owned a travel agency and later became a secretary for the church.

Millie began modeling at the age of 21 and became a regular bikini model on the hit Hispanic TV show Estudio 2 (2005).

In 2009 she landed her first lead film role in Tina Randolph McCulloch's The Virgin Murders. (2009). Her role as the young victim earned her rave reviews. Shortly after she landed roles in bigger projects, such as Cinemax's Life On Top (2009), It's Always Sunny In Philadelphia (2010) alongside Danny DeVito, Hollywood Sex Wars (2011) and Paranormal Whacktivity (2013).

Millie also appeared on Al Extremo (2009), 12 Corazones (2009-2010) and Playboy TV's Foursome (2010).