According to Cruise Industry News, the company has been working with the islands' owner Ian Gowrie-Smith to bring visitors on the liner Pacific Jewel, scheduled to arrive in June 2016.
The move has been described by P&O as a "landmark partnership", with senior vice president Sture Myrmell saying: "We have been pioneering cruising in the Pacific for eight decades and are still discovering fantastic cruise destinations for our guests.
"PNG is one of the most extraordinary places on earth and even though it's our neighbour, it's picturesque islands are relatively untraveled.
"With the expansion of our fleet between 2015 and 2017, the destination and itinerary possibilities are endless, we're taking modern Australian cruise holidays to the next level in the coming years."
In an article in the April/May issue of PNG Report, Gowrie Smith said his intention for buying the Conflict Islands - one of only a few parcels of land to be owned freehold in PNG - was never to sell, but rather protect them.
"My goal is to preserve and protect this untouched ecosystem and I am seeking to find individuals or foundations to partner with me so we can protect the islands and sustainably develop them," he said at the time.