McPhee, 35, who was the runner-up in the 2006 season of "American Idol" and starred in the television series "Scorpion," married Foster, 69, at the Church of Saint Yeghiche before 150 guests, the magazine reported.
The newlyweds' reception was held at an upscale venue in London's Mayfair section, Us magazine reported.
McPhee wrote on Instagram before the wedding, celebrating a life "full of beautiful coincidences.",
“Exactly 13 years ago today my very first single, Somewhere Over The Rainbow, was released right after Idol. Today… I’m marrying the man who produced it. Life is full of beautiful coincidences, isn’t it? Thank you for taking me over the rainbow, David.”