Chicago-based Philpott will take over the company's leadership role in September.
Chedore, who was appointed CEO of Synovate (then Aegis Research) in 2001, will continue on the Aegis board of directors until year-end and will act as a consultant for Synovate and Aegis on specific projects.
He said: "It's been an incredible eight years. It's hard to believe that the Synovate name is only six years old. I think we can all be very proud of the growth and success we have achieved.
"I think it's fair to say we've arrived and I can't think of a better, more capable leader than Robert to lead the company into its next phase."
Philpott has been with Synovate since 1996, serving in various roles across the Americas, Western Europe and the Asia Pacific region prior to taking up his global responsibilities.
Philpott said: "Adrian leaves a strong legacy in Synovate, and I look forward to building upon the dynamic culture he has created.
"Despite the challenges of the current economic environment I believe that Synovate has the talent and client focus to ensure that the Synovate story of success will endure."
Philpott moved to Chicago in 2003 from Hong Kong, where he served as director, responsible for managing Synovate's business across 11 Asia Pacific countries.
He established the firm's presence in Malaysia in 1997, with much of his research work centred around large-scale multi-country projects for a variety of blue-chip clients.
Chedore was one of the founders of Asia Market Intelligence in 1991, which was acquired by Aegis in 2000.
Prior to that, he served as regional managing director of Frank Small & Associates in Asia Pacific.
He joined AGB McNair in Hong Kong as managing director in 1979. Before moving to Asia, Chedore held positions in research, brand management and advertising in the UK.