The TV veteran first rose to fame in 1982 as a crime fighter in Knight Rider, later riding the wave of success to become a lead character in long-running beachside drama Baywatch, which premiered in 1989.
After spending more than four decades in the business, Hasselhoff has developed a new fan base with guest turns in Dodgeball: A True Underdog Story, teen adventure film Eurotrip and Adam Sandler's Click.
In honour of Hasselhoff's big day, WENN has compiled a list of 10 fun facts to commemorate his major milestone.
- Hasselhoff, who is of German descent, has a large following in the country although he doesn't speak the native language. For all German TV shows and movies, his dubbing is completed by actor Andreas von der Meden, who also voices The Muppets' Kermit the Frog.
- He is an outdoor sports enthusiast - the adrenaline-loving star's hobbies include scuba diving, racing cars and white water rafting. He's also parachuted with the U.S. Army Parachute Demonstration Team and flown with The Blue Angels of the U.S. Navy.
- Hasselhoff launched a successful side career as a singer in Europe during the 1980s with breakthrough single Looking for Freedom and he was invited to perform the track on the Berlin Wall on New Year's Eve in 1989 after being named the Most Popular and Best Selling Artist of the Year in Germany.
- He made his Broadway debut as the titular character in Jekyll & Hyde: The Musical in 1995. He has since performed in a number of other stage shows, including Grease, Jesus Christ Superstar and The Rocky Horror Show.
- The actor, who played lifeguard Mitch Buchannon on Baywatch, became a real-life hero after he saved a two-year-old girl from drowning in Malibu, California while at a beach photo shoot in 1995. He also rescued an unconscious car-crash victim in Los Angeles that same year.
- In 2010, Hasselhoff was the the subject of a Comedy Central Roast hosted by Family Guy creator Seth MacFarlane. Wrestler Hulk Hogan and his Baywatch co-stars Pamela Anderson and Traci Bingham also poked fun at the Hoff.
- He originally held the Guinness Book of World Records title for The Most Watched TV Star in the World but House actor Hugh Laurie stole his crown last year (11).
- Hasselhoff loves reality television - he judged America's Got Talent for four years, beginning in 2006, participated in U.S. programme Dancing With the Stars in 2010, presided over the panel of Britain's Got Talent in 2011 and earlier this year (12) competed in Celebrity Apprentice Australia.
- The actor has two grown daughters with ex-wife Pamela Bach - Taylor Ann, 22, and Hayley, 19, an aspiring actress.
- He graduated from Lyons Township High School in La Grange, Illinois in 1970 and a plaque with his photo now hangs on display in the main corridor. Hasselhoff was a member of his school's speech team, president of the choir, and captain of the volleyball team.