Walker was born in Glendale, California to Paul William Walker III (a retired sewer contractor) and Cheryl Crabtree (a former fashion model); his paternal grandfather, William Walker, was a Pearl Harbor survivor and a Navy middleweight boxing champion, while his maternal grandfather commanded a tank Battalion that invaded Italy under General Patton during WWII . He has two younger brothers, Caleb and Cody, and a younger sister, Ashlie.

Walker was raised a Latter Day Saint in a conservative Mormon household. He grew up in Los Angeles' San Fernando Valley and attended Village Christian High School, graduating in 1991. During his late teen years, he was briefly involved in a felony, although the charge has been reduced and he has no criminal record. He attended several community colleges and studied marine biology.

Walker began modeling in the late 1980s. He began his acting career with appearances in several low-budget "B movies", including Monster in the Closet (1987) and Tammy and the T-Rex (1994). He also had a brief stint on the soap opera The Young and the Restless in 1993. In 1998, he starred in his first widely released film, the critically-derided Meet the Deedles, as well as the well-received Pleasantville, playing a high-school basketball player opposite Reese Witherspoon. Between 1999 and 2001, Walker appeared in a few notable films aimed at a teenage audience, including She's All That and Varsity Blues.

His breakthrough came in 2001, when he starred opposite Vin Diesel in the highly successful action film The Fast and the Furious, which established Walker as a notable film star and leading man. Consequently, Walker played the lead role in a number of action-adventure films, the most financially successful of which was 2 Fast 2 Furious (2003). His other 2001 film, Joy Ride, received very positive reviews by critics. Walker was also originally set to star in the film S.W.A.T. (2003), but left the project and was replaced by Colin Farrell.

In February 2001, Walker was named Most Beautiful Man of the month on the web site mostbeautifulman.com. And the following year, in 2002, he was chosen by People Magazine as one of the "50 most beautiful people in the world".

In February 2006, Walker starred in two films; Running Scared, an action thriller, and Eight Below, an adventure set in Antarctica. Eight Below, a family-friendly Disney film, opened in first place at the box office, grossing over $24 million during its first four days. The film received positive reviews and was considered a success for Walker, whose most recent films, including Timeline and Into the Blue, were financial and critical failures. Walker filmed Running Scared in 2004, wanting to participate in a darker-edged film; the film's director, Wayne Kramer, has commented that the film's character is closer to Walker's own personality than any of his previous roles.

Walker is also currently filming a part in Flags of our Fathers, a war movie directed by Clint Eastwood.

Walker currently resides in Santa Barbara and Huntington Beach, California, where he enjoys surfing. He has a daughter, Meadow Rain (born January 28, 1999) from a former girlfriend; she lives with her mother in Hawaii. One of his close friends is actor Scott Caan, who appeared alongside Walker in several films, including Varsity Blues and Into the Blue. He also formed a close friendship with Tyrese Gibson during the filming of 2 Fast 2 Furious.

Walker's religion is still a part of his life, although he is not a practicing Mormon. He is known to practice Brazilian Jiu-Jitsu video clip and enjoys travelling, having visited India, Fiji and Costa Rica among others.

Walker owns a Beagle, a Chesapeake Bay puppy and a horse named Cowboy.