P&O Cruises Australia is a British-American owned cruise line with operational headquarters as part of Carnival Australia, based in Chatswood, New South Wales, Australia. Originally a sister company of P&O Cruises in the United Kingdom, it was previously a constituent of the Peninsular & Oriental Steam Navigation Company and has a direct link in history to the world's first cruise ships. As such, it is one of the oldest cruise lines in the world, and now forms part of the Carnival Corporation & plc, managed locally by Carnival Australia. It currently operates three ships, sailing from various ports in Australia and New Zealand.