Trivia: Received a star on the Hollywood Walk of Fame; it is next to his father's star. [October 1999] Ex-son-in-law of Anthony W. Marshall. Ex-stepfather of Tracy Reiner. Son of Estelle Reiner and Carl Reiner. In 1998, Reiner spearheaded a ballot initiative in California to add a tax on cigarettes to pay for early childhood development programs. It passed by a narrow margin. He has 3 children with wife Michele Singer. Brother of painter Lucas Reiner and poet, playwright and author Annie Reiner. Co-wrote the 1st episode of "Happy Days" (1974).

Supported Al Gore during the 2000 presidential election. In his first project following "All in the Family" (1971), Rob Reiner produced, co-wrote and co-starred with then wife Penny Marshall in the TV movie More Than Friends (1978) (TV), a romantic comedy based on the couple's own courtship. Directed three of the movies ranked in American Film Institute's list of top 100 U.S. love stories in 2002: When Harry Met Sally... (1989) ranked #25, The American President (1995) - #75 and The Princess Bride (1987)- #88. Named his production company "Castle Rock" after a fictional town created by Stephen King (the two have worked as a team on several movies together). While filming the scene in Stand by Me (1986) in which Gordie and Vern are being chased by a train, he couldn't get Wil Wheaton and Jerry O'Connell to look frightened enough, so after a take, he proceeded to yell at them until they began to cry. He then filmed the scene over again.

He graduated from Beverly Hills High School in 1964. Other famous alumni include Angelina Jolie, Michael Klesic, Nicolas Cage, Lenny Kravitz, David Schwimmer, Jonathan Silverman, Gina Gershon, Rhonda Fleming, Jackie Cooper, Antonio Sabato Jr., Pauly Shore, Michael Tolkin, Betty White, Corbin Bernsen, Elizabeth Daily, Albert Brooks and Crispin Glover. Replaced Ted Griffin as the director of Rumor Has It... (2005) twelve days into principal photography. Is a big fan of The Beach Boys. Wore a toupee in "All in the Family" (1971).