David Foster and Katharine McPhee are engaged.

Katharine McPhee and David Foster

Katharine McPhee and David Foster

The 68-year-old musician and the 'Scorpion' actress are set to tie the knot after David got down on one knee whilst the pair were vacationing in Italy recently.

Katharine was spotted showing off her engagement ring to her friends and family on FaceTime and her representative has confirmed to TMZ that the pair are engaged.

At the end of last year, Katharine revealed she had been friends with David - who is the ex-husband of reality television star Yolanda Hadid - for years before their relationship became romantic.

She shared: "We're very close friends, and we've been friends for a long time. I'm really, really fond of him, and I think he's an incredible person. I've known him since I was 21 years old, you know? He produced my first single. So he's been really good to me. People can say whatever they want."

A source previously revealed David is "getting more serious" with Katharine and they are "really comfortable" with each other.

An insider said: "David and Katharine are more serious than they ever have been, and don't care what others around them think. David and Katherine have been spending a lot of time together recently and are not afraid to show affection now.

"David is usually a playboy but Katharine has made him change his ways, and he is really comfortable with her. He tries to fit Katharine into his schedule with dinners and lunches during the week. They both love being out in public together, and are enjoying each other's company. Katharine has always had a crush on David, and she's happy that their relationship is transpiring."