O&M will be the lead creative and strategic UK agency for Pizza Hut, which has previously used Abbott Mead Vickers BBDO and most recently worked with McCann Manchester.
O&M, which was awarded the UK business without a pitch, already works with Yum! Brands, including Pizza Hut, in other global markets.
The agency has been asked to develop a series of integrated campaigns to make Pizza Hut more relevant for today’s consumers.
Sandeep Kataria, the general manager of Pizza Hut UK and Ireland, said: "We want to tap into the creative excellence and strategic rigour synonymous with the Ogilvy network."
Campaign revealed last month that the restaurant chain Pizza Hut UK, which is now a separate company, had kicked off a creative review.