"He's a keeper," Monk said on the Australia radio station 2Day FM after dropping the news that "I got engaged!"
"It feels right," she added. "I think you know when you know."
Her new fiancé, 50, is the chairman of United Licensing Group, which owns the rights to the Playboy brand, and is also involved with Elite Modeling Agency, according to The Sydney Morning Herald.
Monk, 31, revealed on the radio that Esebag is of French origin and that the pair were friends for some time before getting engaged.
She was engaged to Benji Madden in 2006, but the pair called it off in 2008. She had also previously been romantically linked to Ryan Seacrest.
Of Esebag, Monk recently posted on her Facebook page, "It's going to be a good year. My best friend of a long, long time just happens to be my soul partner; funny how life takes you where you are finally meant to be."