Parker will join OMD UK’s board and will lead accounts including SSE, the UK’s second-largest energy supplier and an account the agency won in November 2013.
She will start in March and report directly to Dan Clays, OMD UK’s managing director.
Parker joins OMD UK after more than 11 years at Havas, latterly as head of planning, but also in a range of client-facing roles.
She has led key Havas clients, including another energy brand, EDF energy and the building society Nationwide. Before joining Havas, Parker worked at Initiative and Express Newspapers.
Clays said: "Kelly’s brilliant. A super-smart media planner, first-class operator with clients, comes with tonnes of energy and will fit in perfectly with the culture at OMD UK."
Parker is OMD UK’s second recent high-profile strategy hire from Havas Media. Last year it recruited Hamid Habib, the managing partner of strategy at Havas, as a joint managing partner of strategy with Rian Shah.
Clays added: "We’ve built an exciting team here that will be even stronger with Kelly’s arrival."