Lidbury will be responsible for driving creative and growing Imagination's global automotive business, with clients including Aston Martin, Jaguar, Land Rover and Mazda.
He will work with Imagination European creative director Julian Baker.
Lidbury's previous experience includes working for brands across the globe including Benetton, Diageo, Wedgwood, and Saville Row.
Baker said: "We are excited to have Steve on board; his role at Imagination will enhance our ability to create award-winning work that connects audiences to brands in powerful and memorable ways."
Lidbury added: "The automotive division is working with clients for high quality and authentic, premium international brands, and I see a lot of scope in terms of how I can bring a fresh approach and new way of thinking to stimulate this sector."