McCoy joins the EDF media team after three years at Starbucks, which he joined as director of comms from Blue Rubicon in 2009.
He replaces former head of media relations Kaa Holmes, who has been promoted to the role of employee relations and engagement director.
McCoy will report to EDF Energy's brand sustainability and external comms director, Andrew Brown.
Commenting on his new role, McCoy said: 'The industry as a whole is undergoing major change as we address the need for clean, secure and affordable energy for the future.
'EDF Energy is at the vanguard of all of this as the company that runs most of the country's nuclear power stations, and is the largest supplier of low-carbon electricity.'
Last month, PRWeek revealed that the French energy firm brought in agency Pagefield to help support its case for building a controversial third nuclear reactor at Sizewell in Suffolk.
McCoy added: 'EDF has also been proactively addressing the consumer trust agenda with a bold set of commitments and industry-leading products. This is an exciting time to get stuck into these issues.'
McCoy spent 14 years at the BBC as a reporter, producer and programme editor for both radio and television news programmes.
He was appointed Blue Rubicon's head of media in 2008.
Brown said: 'Tim joins us at a crucial time for our business, as we approach making a final investment decision in new nuclear builds that will have implications not just in securing low-carbon energy supplies, but for economic growth in the UK.'