Gosselaar was born in Panorama City, California, the son of Paula (van den Brink), a homemaker and hostess for KLM, and Hans Gosselaar, a plant supervisor for Anheuser-Busch. His Dutch father is of German and Dutch Jewish descent. Gosselaar's paternal great-grandparents, Hertog and Hester Gosselaar, were killed at the Sobibor extermination camp during the Holocaust. His mother, who is of Indonesian and Dutch descent, is from Bali, Indonesia. At one point, Gosselaar was fluent in Dutch (his older siblings were born in the Netherlands). Gosselaar's parents later separated.
Gosselaar's mother worked as his manager. He began modeling at the age of 5. As a child, he appeared in commercials for Oreo cookies and Smurf merchandise, and later won guest spots on television series. He spent his teenage years in the Santa Clarita Valley in Southern California, where he attended Hart High School.
Gosselaar first came to public notice as the star of the hit television comedy series Saved by the Bell, in which he played Zack Morris, and which aired on NBC from 1989 to 1993. Gosselaar's character was adapted from the short-lived Disney Channel sitcom Good Morning, Miss Bliss; although that show was cancelled after one season, NBC executives believed that a similar show, with Zack Morris as the series lead, had potential for success. He reprised the role in two TV movies and a less-successful spin-off, Saved by the Bell: The College Years. In 1994, Gosselaar appeared as Zack Morris in a second spin-off series Saved by the Bell: The New Class in the episode "Goodbye, Bayside – Part 2", along with Mario López as A.C. Slater and Lark Voorhies as Lisa Turtle.
In 1996, Gosselaar appeared in the TV-film She Cried No as a college student who date-rapes his best friend's sister at a fraternity party. In 1998, he starred in the feature film, Dead Man on Campus. Later that same year, Gosselaar played the central character in the TV drama Hyperion Bay, which lasted 17 episodes. In 2001, he starred in the movie The Princess and the Marine, with Marisol Nichols. He also starred in the short-lived WB series D.C. From 2001-05, he played Detective John Clark on ABC's NYPD Blue. After the series ended, he joined the cast of ABC's Commander in Chief, which lasted only one season. He appeared on the HBO series John from Cincinnati. He then gained the starring role of defense attorney Jerry Kellerman in the Steven Bochco-produced Raising the Bar, which debuted on September 1, 2008, on TNT, then it was canceled in November 2009 after two seasons.
On June 8, 2009, Gosselaar appeared on Late Night with Jimmy Fallon in character as Zack Morris to promote his show Raising the Bar, indicating that the name Mark-Paul Gosselaar is his stage name and declaring, as Zack, that he would participate in a Saved by the Bell "Class" reunion that is being spearheaded by Fallon. He has since agreed to participate in the reunion being organized by Jimmy Fallon on Late Night with Jimmy Fallon along with four fellow castmembers to date. On February 4, 2015, Gosselaar reunited with Mario Lopez, Elizabeth Berkley, Dennis Haskins and Tiffani Thiessen on The Tonight Show Starring Jimmy Fallon where they appeared in a Saved by the Bell sketch with Fallon.
In October 2009, he made his Off-Broadway stage debut in Theresa Rebeck's play The Understudy with The Roundabout Theatre Company. The show extended its limited New York run until January 17, 2010.
Gosselaar began filming the TNT series Franklin & Bash on March 28, 2010. The series premiered on June 1, 2011. On November 11, 2014, it was announced that the series was canceled, after four seasons.
The FOX series Pitch cast Gosselaar in the main role of Mike Lawson, star catcher and team captain, in February 2016, and premiered on September 22, 2016. On May 1, 2017, it was announced that the series was canceled, after one season.
In a July 2009 interview with People magazine, Gosselaar revealed that when Saved By the Bell was in production, he dated, at different times, his three female co-stars: Lark Voorhies, Tiffani Thiessen and Elizabeth Berkley. He remains friends with his Saved by the Bell cast mates.
In 1996, Gosselaar married former model Lisa Ann Russell. Together they have two children: son Michael Charles (born 2004) and daughter Ava Lorenn (born 2006). After 14 years of marriage, Gosselaar and Russell announced their separation in early June 2010. Gosselaar filed for divorce June 18, 2010, and it became final in May 2011.
Gosselaar was engaged to advertising executive Catriona McGinn in August 2011. They married July 28, 2012 at the Sunstone winery in Santa Ynez, California. They have a son Dekker (born 2013), and a daughter Lachlyn (born 2015).
Gosselaar is a sports car enthusiast, race car driver, track cyclist, dirt biker and pilot. In 2005, he competed in the Far West Championships for track cycling. He won the Category 4/5 Sprint Championship event at the Encino Velodrome.
Young Artist Award1989: Nominated, Best Young Actor in a Cable Family Series – Good Morning, Miss Bliss
1990: Nominated, Outstanding Young Ensemble Cast – Saved by the Bell
1991: Best Young Actor Starring in an Off-Primetime Series – Saved by the Bell
1992: Nominated, Best Young Actor Starring in an Off-Primetime Series – Saved by the Bell
1993: Nominated, Best Young Actor Starring in an Off-Primetime Series – Saved by the Bell