The agency has hired Mother's Mark Harrison as the managing director of retail, Lawrence Weber from The Brooklyn Brothers as the head of digital integration and David Pandit, who joins from Bartle Bogle Hegarty as the director of data and analytics.
Harrison was previously the head of retail development at Mother, where he ran the Boots and Ikea accounts.
Weber has been The Brooklyn Brothers' head of digital production since 2009. He was responsible for managing the digital output, including the award-winning "being Henry" film for Range Rover.
Pandit was previously the head of data at BBH and built its data function.
Ben Bilboul, Karmarama's group chief executive, said: "As well as having a great creative pedigree, all three share our ambition to offer clients solutions that can work across the entire customer journey."