After a lengthy campaign, P&O Cruises were permitted to allocate the new Oriana with the call sign 'GVSN', which is the same call sign as her predecessor namesake (the Oriana built in 1960). One of her main designers, Robert Tillberg, spent a lot of the time onboard Canberra investigating the needs of British passengers and including as many features of Canberra possible into Oriana's design. The Oriana's single funnel is designed to have a resemblance to Canberra's twin funnels. She also has a single deck of balconies reserved for Suites, Mini-suites and Staterooms to cater for the growing desire for balconies onboard.

When she entered service Oriana was one of the largest cruise ships in the world, and also the largest ship built in Germany since 1914. Since then tonnages have boomed as the economies of scale dictate that a larger ships generates more profit. Nowadays most new cruise ships have a GRT of around 100,000 tonnes or higher.

She then set sail on her maiden voyage on the 9th April 1995 which was a cruise from Southampton to Scandinavia. Since then she has enjoyed a successful career with P&O Cruises and throughout the spring, summer and autumn, Oriana sails to the Mediterranean, Baltic, Scandinavia and the Caribbean. January to March each year sees her undertaking her annual World Cruise, calling at nearly 30 ports of call and taking 90 days to complete.

The Oriana currently holds the Golden Cockerel trophy for the fastest ship in the P&O Cruises fleet. Previously held by the S.S. Oriana (1960) it passed to S.S. Canberra after that Oriana's retirement in 1986. On Canberra's final cruise in 1997 the Golden Cockerel was handed over to the new Oriana when both ships were anchored off Cannes and sent boats out to perform the handover.

In December 2006 a £12 million refit was undertaken on the Oriana in Bremerhaven, Germany. During the refit she was reflagged from the British Red Ensign to the Bermuda flag in order to enable Weddings at Sea to be held on board. Also a new Oriana Rhodes restaurant, designed by celebrity chef Gary Rhodes was introduced. Created in what was formerly 'The Curzon Room', the 96 seater restaurant has been introduced due to the success of the Arcadian Rhodes restaurant on fleetmate Arcadia. Other modifications included the extension of the popular Lord's Tavern bar, festooned with cricket memorabilia and refurbishment of the children's play areas. In addition all of her cabins have been restyled to include one of four new colour schemes, new curtains, carpets, beds, linen and duvets.

Today she continues to sail for P&O Cruises and remains a firm favourite with the British cruise market.