The actor's representative told People.com Gosselaar's wife, advertising executive Catriona McGinn, gave birth to their first child, son Dekker Edward Gosselaar, Monday.
"We are overjoyed with the new addition to our family. We are madly in love with our little boy," the "Franklin & Bash" leading man told the magazine. "He is healthy and just perfect -- all we could ask for."
Gosselaar is also the father of Ava Lorenn, 7, and Michael Charles, 9, from a previous marriage.