The former Celebrity Apprentice star popped the question to Price while recently on a romantic holiday, according to The Huffington Post.
Stone revealed: "We were in Italy for the week and I got my romance on. I wrote her a love letter and popped the question. Got down on one knee. I picked [the ring] myself.
"It was one of the most nerve-racking, bloody weeks of my life because I walked around with it. I was in Naples for a couple of days and Naples isn't the safest place. I was confident [she would say yes]."
No wedding has yet been set by the couple.
Price, a former Beverly Hills, 90210 star, began dating Stone in late 2009. She was previously married to Dead Zone creator Shawn Piller.
Stone and Price welcomed baby son Hudson in November 2011.
Watch Curtis Stone in a clip from The Celebrity Apprentice below: