Williams was born Anson william Heimlich to Jewish family. His father, Haskell Heimlich, legally changed the spelling of the family name to "Heimlick", unlike Williams' uncle, Dr. Henry Heimlich, namesake of the Heimlich maneuver for treating choking victims. Williams attended Burbank High School, where he was captain of the track team and acted in multiple school productions. In 1971, he appeared with John Amos in a commercial for McDonald's.
In 1972, Williams landed the role of Potsie Weber in a segment of the comedy-anthology series Love, American Style titled "Love and the Happy Days", which also introduced Richie Cunningham (Ron Howard), Richie's mother Marion (Marion Ross), and other characters that were spun off into the television series Happy Days. (Only Williams, Howard, and Ross reprised their roles for the spin-off). The new series' first season, during which Williams received second billing after Howard, was centered mainly on Richie and Potsie. Eventually, as break-out character Arthur "Fonzie" Fonzarelli (Henry Winkler) and Richie's mother, father, and sister became more popular, Potsie was joined by Ralph Malph (Don Most, who was merely a side character in season one), and Potsie and Ralph became inseparable.
After Happy Days, Williams began a much more prolific career as a television Director, starting with short programs for adolescent-age children, including afterschool specials "No Greater Gift" (1985) and "The Drug Knot" (1986), and TV-movie Lone Star Kid (1986). He has gone on to direct many episodes for a variety of television series, including The Pretender, Beverly Hills, 90210, Melrose Place, seaQuest DSV, Star Trek: Deep Space Nine, Star Trek: Voyager, Xena: Warrior Princess, Hercules: The Legendary Journeys, The Secret Life of the American Teenager, Sabrina the Teenage Witch, and Charmed. He also directed several episodes of the TV series 7th Heaven.
Williams is also a businessman. In 1987, fellow Happy Days cast member Al Molinaro and he opened a chain of diners called Big Al's; the Business went defunct. He founded Starmaker Products, a cosmetics company, and was a featured speaker at the U.S. Patent and Trademark Office's National Trademark Expo in April 2008, at which he talked about the importance of registered trademarks for small businesses (and signed autographs for Happy Days fans). Williams is the author of Singing to a Bulldog: From Happy Days to Hollywood Director, and the Unlikely Mentor Who Got Me There.
Despite his success as a Director and Producer, Williams has occasionally returned to his work on Happy Days in retrospective ways. He played himself in a 1996 Happy Days-themed Boy Meets World episode (which also featured former castmates Tom Bosley and Pat Morita). While directing a 2003 episode of Sabrina the Teenage Witch titled "Sabrina in Wonderland", he appeared as Potsie in a fantasy sequence. He also joined his fellow Happy Days cast members for reunion specials in 1992 and 2005.
On April 19, 2011, Williams and four of his Happy Days co-stars, Erin Moran, Don Most, Marion Ross and the estate of Tom Bosley, who died in 2010, filed a $10 million breach-of-contract lawsuit against CBS, which owns the show, claiming they had not been paid for merchandising revenues owed under their contracts. The cast members claimed they had not received revenues from show-related items, including comic books, T-shirts, scrapbooks, trading cards, games, lunch boxes, dolls, toy cars, magnets, greeting cards, and DVDs, where their images appear on the box covers. Under their contracts, they were supposed to be paid 5% from the net proceeds of merchandising if their sole images were used, and half that amount if they were in a group. CBS said it owed the actors $8,500 and $9,000 each, most of it from slot machine revenues, but the group said they were owed millions. The lawsuit was initiated after Ross was informed by a friend playing slots at a casino of a "Happy Days" machine on which players win the jackpot when five Marion Rosses are rolled.
In October 2011, a judge rejected the group's fraud claim, which meant they could not receive millions of dollars in potential damages. On June 5, 2012, a judge denied a motion filed by CBS to have the case thrown out, which meant it would go to trial on July 17 if the matter were not settled by then. In July 2012, the actors settled their lawsuit with CBS. Each received a payment of $65,000 and a promise by CBS to continue honoring the terms of their contracts. Williams said, "I'm very satisfied with the settlement. And that's all I can say."
