The 50-year-old Cougar Town star was snapped leaving Craig's restaurant in West Hollywood, wearing her new bling alongside another ring she wears daily.
To pick out the ring, McDaid, 37, sought advice from Cox's closest pals. "He worked hard to get one that was elegant and tasteful," an insider tells Us Weekly. "He asked people close to her for help."
The British musician was a true gentleman before popping the question in Turks and Caicos during a vacation celebrating Cox's 50th birthday. "Johnny asked [Courteney's mom] Cece for permission to propose," another insider tells Us.
"It was just the two of them, very sweet and romantic and between them," the source adds of the proposal. "Johnny is so in love with her and she knows this is right."
Cox and McDaid were first spotted out together in December 2013. It's the first marriage for McDaid and the second for Cox, who was previously married to David Arquette for nearly 14 years.