The Baywatch actor popped the question to girlfriend Hayley Roberts after nearly five years of dating, reports Hello! Magazine.
Hasselhoff, 63, surprised Roberts, 36, with the proposal while on a romantic beachside picnic in Malibu.
"We were both in tears … I genuinely had no idea he was going to do that," Roberts told Hello! of the romantic gesture. "I'm still overwhelmed."
The actor admitted that he mulled over the decision to propose or not due to their 27-year age gap, but ultimately decided their love was strong enough to withstand any obstacles.
"I had a saying, 'You don't get married because you want to live with someone, you get married because you can't live without them,' " he said. "I felt that way. I knew that I was really unhappy without her. I waited to propose because I thought I was too old for her."
But Roberts said their age gap never bothered her. "I don't worry about it. I don't want to miss out on being with someone I love because of what might happen down the line."
And when the big moment finally came, Roberts said it took her a few minutes to grasp what was really happening.
"I thought he was just joking around at first," she said. "He's asked me before, but it was never for real. Then he pulled out the ring. I cried so hard that he didn't get around to actually asking, 'Will you marry me?' until about ten minutes later."
"I've asked her to marry me before but those times were for fun," added Hasselhoff. "This time, it was special and from my heart."
The actor acknowledged the engagement on Twitter, thanking his fans for their well-wishes.
"HELLO! Tanks for all Congratulations to me & Hayley," he wrote.
HELLO ! Thanks for all Congratulations to me & Hayley&GUMBALL &2nd season premiere of Hoff The Record on Dave this Friday ! BEST WEEK EVER!— David Hasselhoff (@DavidHasselhoff) May 3, 2016
This will mark Hasselhoff's third trip down the isle, as he was previously married to singer Catherine Hickland from 1984-1989. He later tied the knot with Pamela Bach in 1989, but later called it quits after seven years of marriage.
Bach and Hasselhoff have two daughters together: Hayley, 23, and Taylor, 25.
The actor said both of his daughters are supportive of his relationship with Roberts.
"I told my girls what I was going to do and they were both really supportive," he said. "It's tough. No one wants to see their parents split up. But they love Hayley and they're just happy for me."