Starcom, part of Starcom MediaVest Group, beat UM London, Maxus and the incumbent, Havas Media, to win the business, which is estimated to be worth £5 million in the UK.
The account also includes all activity in Ireland, Germany, France, Belgium, Poland and the Netherlands.
MRM Meteorite picked up the creative business, which includes strategy, ahead of Lida and Kittcat Nohr, following a review revealed by Campaign in April.
P&O Ferries has charged the Publicis Groupe agency with developing a media strategy centred on its customers. Starcom will also develop the ferry company’s use of digital in a bid to improve the effectiveness of its marketing.
Sarah Rosier, the head of marketing and sales at P&O Ferries, said: "Starcom is a great fit for our business at a time when we are integrating our channels further and developing our strategy.
"With a real understanding of our market and business objectives, they demonstrated some excellent ideas and bought new thinking and energy in their approach. We can’t wait to start working on the strategy ahead."
Starcom takes over the business on Monday 4 August. MRM Meteorite is already working on the business.
Pippa Glucklich, the co-chief executive at Starcom MediaVest Group, said: "We will bring a new approach and rigour that lives up to this great brand and will deliver human experiences that engage and capture the imagination of P&O Ferries' customers."