The iconic sitcom ran from 1989 to 1993.
The 44-year-old actor was a guest on Anna Faris' Unqualified podcast earlier this week and revealed that Zack Morris and Jessie Spano were an off-screen item during some of the run of the teen show, which ran from 1989 to 1993.
"We dated. If you want to call it dating, sure," he said of Berkley, 46. "You're in an environment, you know how it is when you're working on a set, and we were young, I mean we were young. There's no one around really. I mean, you work and live in a bubble."
"You're in L.A., right. You're in your cars and you come to set and you do your work and you're with these beautiful women and then you go back in your car," he continued. "You're not going to school, so you don't have a lot of choices. People say, ‘Well didn't you go out?' Not really."
While he and Berkley had an off-screen romance, Gosselaar was being driven to work by either his mom or manager and had no idea about his teen heartthrob status.
"No social media. The only barometer was whether or not you were on Teen Beat, on the cover. If you weren't on the cover you weren't sh*t," he said. "And the other one was if you went to a mall signing and depending on and depending on the crowd size. So you go to The Mall of America and you do a crowd signing, if 2,500 people show up you're like, 'Oh, I'm pretty hot sh*t.' But that's pretty much it. Or people come to the show, it's taped in front of a live audience."
"There was really no way to gauge how big you were," he added.
All that success "came to an abrupt end" for the actor when Saved by the Bell: The College Years wrapped in 1994 and he, after deciding to officially pursue acting as a career, didn't work for two years.
"It was two years of not knowing where my paycheck was going to come from," he said. "I was detailing cars with my cousin and trying to find my life. It was important because I thought at first my sh*t didn't stink... It humbled me to the point of now I understood how important and how much of a blessing it is that we get to do this for a living."
Though he's certainly thankful for his Saved by the Bell days, Gosselaar admitted that it would be a "deal-breaker" if a girlfriend referred to him as his iconic character in the bedroom.
"That'd be a deal-breaker. That'd be a deal-breaker," he reiterated. "It really would. Yeah, no. Sorry... I wouldn't trust anything that came out of her mouth afterwards. At the point everything is based on a character that I played rather than me... I'd never been in that position. It'd just feel so icky. I'd feel really weird about the whole thing."
ET recently caught up with the actor on the set of his show, The Passage. Watch the video below to see what he had to say:
Mark-Paul Gosselaar Says He Hasn't Spoken to His 'Saved by the Bell' Co-Star Dustin Diamond in 25 Years
Tiffani Thiessen Recalls Drinking Wine in Paris at 16 With 'Saved By the Bell' Co-Star Mark-Paul Gosselaar