The line says its newest programme features 160 cruises, with Iona set for its first deployment in the Norwegian fjords.
It also features new itineraries in the Mediterranean, Norway, Iceland and the UK in Europe, and North America.
These include a new 30-night itinerary on Arcadia in September 2020, which includes an overnight stop in Boston and three days in New York.
Iona will sail the Norwegian fjords between May and September 2020.
P&O has also announced Arcadia will sail a northern lights cruise in October 2020, while Aurora will head to Iceland in summer 2020 calling overnight in capital Reykjavik and stopping in Isafjordur and Akureyri.
Pre-registration opened on Monday (September 3). Iona will go on sale to Top Tier Peninsula Club members from September 10 before going on general sale from September 12.
The rest of P&O’s summer 2020 programme will go on sale to Top Tier members on September 17 and general sale on September 19.
Paul Ludlow, P&O Cruises senior vice-president, said: “This is the year for those who have never considered a cruise to see the broadest range of stunning ports and exclusive dining experiences.
“The brochure also features Iona’s inaugural season in the Norwegian fjords, a destination that should only be experienced by sea to appreciate fully the spectacular landscape and activities.
The line is offering 5% deposits on all cruises in the summer 2020 programme until December 3. The offer can be combined with other P&O select prices or early saver fares.