Minogue was recovering in her hometown of Melbourne after a cancerous lump was successfully removed from her breast Friday. Doctors were confident they had caught the disease early enough to prevent it from spreading.
The Daily Telegraph newspaper in Sydney printed a photo Monday of the singer wearing dark glasses and holding Martinez's hand as she left a Melbourne hospital.
No details of her follow-up treatment have been released.
Martinez was quoted as saying the couple had been planning to have a child.
"We were going to start working on it after the tour was over," the French actor was quoted as telling New Idea magazine. "Now it will be put off; not forever — we pray and hope — but for the time being."
Minogue, who will be 37 on Saturday, has called off a tour of Australia and Asia.
A message posted on her Web site said the pop star "has friends and family around her, and her spirits are high."
Olivier co-starred with Diane Lane in the 2002 film "Unfaithful."