The 61-year-old model was spotted enjoying dinner with the 63-year-old singer - who has been single since splitting from Meg Ryan last year - in New York City on Monday (14.09.15), fuelling speculation they are dating.
The casually-dressed pair - who had arrived separately - appeared happy and relaxed as they left the Bowery Hotel and got into the 'Jack & Diane' singer's chauffeured car.
An onlooker told 'Entertainment Tonight' John seemed affectionate towards Christie, touching her back as they walked.
Christie - who has been married four times and has three children, Alexa Ray, 29, Jack, 20, and Sailor, 17 - has previously admitted it is hard to find love with someone her own age.
She said: ''It seems like during this period that most of the guys are like 38, 39, 42, like that sort of age group.
''It's funny because I think that at that age they have nothing to prove. They're very confident and do just what they want to do. [With] men my age I feel quite invisible to them.
''I think a ten year span is fine.''
The biggest names in music royalty.
One of the most diverse line-ups we've seen for a major awards show in a while.