Rachel Anne McAdams (born November 17, 1978) is a Canadian actress. After graduating from a theatre degree program at York University in 2001, she worked in Canadian television and film productions, such as the drama film Perfect Pie (2002), for which she received a Genie Award nomination, the comedy film My Name Is Tanino (2002), and the comedy series Slings and Arrows (2003–2005), for which she won a Gemini Award.

In 2002, she made her Hollywood film debut in the comedy The Hot Chick. She rose to fame in 2004 with the comedy Mean Girls and the romantic drama The Notebook. In 2005, she starred in the romantic comedy Wedding Crashers, the psychological thriller Red Eye, and the comedy-drama The Family Stone. She was hailed by the media as Hollywood's new "it girl", and received a BAFTA Award nomination for Best Rising Star.

After a brief sabbatical, she returned to prominence in 2009, by appearing in the political thriller State of Play, the romance The Time Traveler's Wife, and the 2009 mystery film Sherlock Holmes. In 2010, McAdams appeared in the star vehicle comedy film Morning Glory, and went on to star in the films Midnight in Paris (2011), The Vow (2012), and About Time (2013). In 2015, she starred in the second season of the HBO anthology crime drama series True Detective, and portrayed the journalist Sacha Pfeiffer in the drama Spotlight. For the latter, she was nominated for the Academy Award for Best Supporting Actress. This was followed by roles in the superhero film Doctor Strange (2016), the romantic drama Disobedience (2017), the comedies Game Night (2018) and Eurovision Song Contest: The Story of Fire Saga (2020), the superhero sequel Doctor Strange in the Multiverse of Madness (2022) and the coming-of-age drama Are You There God? It’s Me, Margaret (2023).