Frederick Christopher "Chris" Klein (born March 14, 1979) is an American movie actor. He is perhaps best known for playing Chris "Oz" Ostreicher in American Pie.

Klein was born and raised in Hinsdale, Illinois, the son of Terry, a kindergarten teacher, and Frank Klein, an engineer. Klein was the second of three children. His older sister Debbie was born in 1978, and his younger brother was born in 1982. As a child, Klein had his first on stage experience by singing “This Little Light of Mine” in a community theater at the Sheraton Convention Center in Chicago. He lived in the town for thirteen years before his family moved to Omaha, Nebraska. At Millard West High School, Klein acted in his high school's performance of West Side Story, and played quarterback and linebacker for the football team. In his senior year, Klein was offered his first professional acting job by director Alexander Payne, who was scouting Omaha, his hometown, as a potential filming location for the film Election. He attended Texas Christian University (TCU) in Fort Worth, Texas.

After auditioning for the film, Payne chose Klein and they began filming. In April 1999, the film was released to positive reviews. Soon after, Klein found a steady amount of work in the film industry while briefly attending Texas Christian University, where he studied theater and was a member of Lambda Chi Alpha fraternity. He was next seen in American Pie, which opened on July 9, 1999, and was a box office success. Klein has subsequently appeared in several films catering to teenage audiences, with the most recent including Just Friends (2005) and American Dreamz (2006).