He will be based in BCW London’s issues and public affairs team and report to managing director for issues and public affairs, Nick Williams.
The director-level role will see Hawkes provide "the very best senior strategic communications advice and media counsel to BCW’s clients across its London office".
Hawkes, who joins BCW in early October, has been in his current role since December 2013, before which he was business editor at The Sun for almost five years.
He has also worked at The Times, The Daily Telegraph, The Mirror, PA and The Evening Standard in a journalism career spanning 25 years.
Scott Wilson, BCW president for Europe and Africa, said: "This is a key marquee hire for BCW UK and once again shows our commitment to hiring the very best communications talent available. Over the last year, BCW has grown significantly as a business. Being able to attract people with Steve’s calibre and experience is another game-changer for us and one which we know will add huge benefit to our clients."
Williams said: "The talent and experience of someone like Steve Hawkes is hard to beat. His knowledge and insight, from everything from politics to business, will be a major asset to our team."
Hawkes said: "I have had a great career in journalism - covering some of the most important stories on some of the UK’s most recognised news outlets. But it’s a perfect time to be moving to BCW and I look forward to working with what is a really impressive mix of people and clients as the agency goes from strength to strength."
BCW, which formed last year with the merger of WPP agencies Burson-Marsteller and Cohn & Wolfe, is the seventh biggest PR agency in the UK, with revenue of an estimated £42.3m and a headcount of 315 in 2018.