Millie Davis is a Canadian actress who played Ms. O/ Big O in the TVOKids/PBS Kids series Odd Squad, Riley in the television show Dino Dana, Summer in Wonder, and Gemma Hendrix in Orphan Black. She was nominated for a Canadian Screen Award for Best Performance by an Actress in a Leading Role in a Dramatic Program or Limited Series as Ms. O in Odd Squad: The Movie at the 5th Canadian Screen Awards and has been co-nominated with the Odd Squad cast for four additional awards, including winning the award for "Best Young Ensemble in a TV Series" at the 2015 Joey Awards.