The former Friends actress arrived at the premiere of her directorial debut Just Before I Go wearing a tight black leather dress and a large ring on her wedding finger. She was with her partner of several months, who is a musician for band Snow Patrol.
However when asked about the engagement rumours which she sparked this week with the jewellery on her left hand ring finger, Courteney simply replied with: "No".
Courteney Cox and Johnny McDaid
Starring Olivia Thirlby, Kate Walsh and Sean William Scott, Just Before I Go focusses on a man who travels to his hometown to make amends as he decides he has given up on life.
Courteney collaborated with Johnny on her new film as he contributed three songs to the soundtrack.
Speaking of the collaboration, Courteney said: "It was great, it actually worked. We really respect each other... and it's been amazing. I've been really lucky because I got three fantastic original songs that were made just for the film and it really elevates the material."
The pair met in December through British singer Ed Sheeran, and Ed recently revealed that Johnny had moved into Courteney's Malibu home.
Courteney Cox wears a large diamond ring
"I'm not sure that it’s public knowledge, so maybe I shouldn't have said anything – but, yes, they're already living together," said Ed, speaking at an exhibition opening in London at the beginning of April.
Asked if wedding bells could soon be sounding for Northern Ireland-born musician Johnny and Courteney, Ed replied: "I wouldn't be surprised, but it's still early days."
Despite only being together for a few months, the romance between the actress and the Derry-born musician is clearly going well.
The pair took a romantic break to Venice for Valentine's Day, and Johnny even flew in his mum and family in to meet his new girlfriend.