Edwards, the director of communications planning, becomes the lead strategist after the departure of Rebecca Moody to Adam & Eve/DDB last year. He will be responsible for integrated strategy function and new-business ventures.
Bowcott takes on the role of planning director and will work across a range of clients and new business.
Edwards joined the agency five years ago from the branded content shop Kameleon, where he was the managing director. He has also worked at Mindshare.
Bowcott was the planning director at Droga5 Sydney until 2012. She previously worked at Bartle Bogle Hegarty as the strategic lead across a variety of accounts.
Russ Lidstone, the chief executive of Havas Worldwide London, said: "Anthony has always brought a brilliant business and channel perspective to the strategic process, and his ability and knowledge need to be applied across everything we do.
Having both worked with Lisa before, we are chuffed to have her join the team."
Edwards added: "I love that our agency is built differently, with strategy at the forefront, bringing fresh thinking to our clients’ businesses."