- Parents immigrated to California from the Netherlands, where his three older siblings were born; his mother is of Indonesian descent.
- A one-time child model, he signed with an agent at age 5 and acted in commercials for Smurfs merchandise and Oreo cookies.
- Made his TV debut in a 1986 episode of Highway to Heaven.
- Met first wife Lisa Ann Russell in 1993 when they worked together on Saved by the Bell: The College Years.
- Has written about motorcycles for Transworld Motocross magazine.
- Replaced Rick Schroder, who was also a child star, as Sipowicz's partner on NYPD Blue in 2001 and stayed until the series ended in 2005.
- Made stage debut in the off-Broadway production of The Understudy in 2009.
- Catriona McGinn — Wife
- Dekker Edward Gosselaar — Son
- Linda Gosselaar — Sister
- Hans Gosselaar — Father
- Lisa Ann Russell — Ex-wife
- Paula Gosselaar — Mother
- Michael Gosselaar — Brother
- Ava Lorenn Gosselaar — Daughter
- Michael Charles Gosselaar — Son
- Sylvia Gosselaar — Sister
- Lachlyn Hope Gosselaar — Daughter
- Birth Name: Mark-Paul Harry Gosselaar
- Birth Place: Panorama City, California, United States
- Birthday: March 1, 1974, Pisces
- Profession: Actor, Model