Armagh Cats Protection took in the ginger cat, only to discover he was originally microchipped in Australia. He was also tagged in a London vet clinic, as a stray, in 2004.
His owners, however, never linked their details to his record. How he got from Australia to London, and then across the Irish sea to Armagh, remains a mystery.
Ozzie's record also shows him to be 25 years old, born in 1989 - though the average life expectancy of cats is only 15 years.
The Guinness World Record for the oldest cat was 38 years and three days - but it's possible that Ozzie's remarkable age is a typing error from when he was chipped.
"I responded to a call from a member of the public last Monday evening who was concerned about a poorly stray cat that had been hanging around her garden for several days in the Laurelvale area outside Portadown," Gillian McMullen from Cats Protection told the Belfast Telegraph.
"The poor cat was starving but obviously had been cared for in the past because it was wearing a collar."
It was then that Ozzie - who was apparently once known as Tigger, according to his microchip - was scanned by the vet at his health check-up.
The group is now interested in tracking down his original owner and unravelling the story of how he managed to get to the far side of the globe.
"We are desperate to unravel the rest of this cat's past and hopefully reunite him with his owners," McMullen told the
"We have been in touch with the Australian Animal Register and have our fingers and paws crossed on word from them on this cat."