Andrea Joy Cook (born July 22, 1978) is a Canadian actress more commonly known as A. J. Cook. She has appeared in several Hollywood films and television shows including The Virgin Suicides, Out Cold, Final Destination 2 and Criminal Minds.

Cook's first job was in a McDonald's commercial in 1997. She graduated to series work with a guest role on the television series Goosebumps, and parts in two television movies, In His Father's Shoes and Elvis Meets Nixon. Cook launched her feature film career as one of five captivating suicidal sisters in 1999's The Virgin Suicides. Also that year, she took a starring role in the TV series Higher Ground, in which Cook played Shelby Merrick – a rough around the edges teenage girl dealing with abuse and heartache at a wilderness school for struggling kids. Higher Ground lasted one season, ending with a romance between Shelby and Hayden Christensen's character, Scott.

After Higher Ground, Cook starred in the 2000 TV movie The Spiral Staircase, and then captured leading roles in several films, including Out Cold and Final Destination 2.

She currently stars as Jennifer "J.J." Jareau in the CBS drama Criminal Minds.