Rachel McAdams was born in St. Thomas, just a few miles south of London, Ontario. When she was four, she took up figure skating and competed throughout high school. However, she knew that she wanted to be an actor one day and attended summer theater camp as well as appearing in school plays. In 1995, she received an acting award for her role in the one-act high school play I Live in a Little Town when it was presented at the prestigious Ontario Showcase at the Sears Drama Festival. McAdams went on to study theater at York University in Toronto, where she appeared in numerous stage and student film productions. During her senior year, she played a child in The Piper, a workshop led by a creative team from Toronto's Necessary Angel Theatre Company.
Her first professional onscreen role came in 2001, playing a girl with bulimia in the Disney series The Famous Jett Jackson, filmed just outside of Toronto. Soon after, she landed a starring role in a pilot for MTV called Shotgun Love Dolls. She also made a guest appearance on Earth: Final Conflict and filmed a role in the TV movie Guilt by Association. McAdams made her film debut in the Canada/Italy co-production My Name is Tanino (2002). The same year, she played a role in the Canadian film Perfect Pie, for which she earned a Genie nomination for Best Supporting Actress.