The loved-up couple were feeling sky-high as they took some time out of their hectic sporting schedule to view Sydney's biggest attractions.
Caroline (22) is preparing for the Australian Open on January 14.
They took in tourist sights such as the famous Sydney Opera House and posed for snaps on one of the city's tallest buildings.
A delighted Caroline proudly told how she had overcome her fear of heights.
The tennis star told fans on Twitter: “Really proud of myself, on top of the world in Sydney with @McIlroyRory!”
And it appears the Dane's relationship with the Co Down golfing superstar is soaring to new heights as she also wrote “Having a great afternoon in Sydney with @McIlroyRory”. Rory (23) is enjoying some downtime as he supports his girlfriend on the tennis circuit. However, controversy over the his 2016 Olympics involvement continues to plague him.
He told a BBC One documentary last night: “It's a tough one. I haven't made a decision yet. I might not play at all because if I do it might upset people. So I have three options: Play for GB, Ireland or not at all.”