NEW YORK—Seth Oster has joined US audit, tax and advisory firm KPMG as chief communications officer. He will oversee all corporate communications, directing the firm’s internal and external communications activities, strategies and staff.

Oster most recently served in the Obama administration as a senior appointee at the U.S. Environmental Protection Agency, and the agency’s top communications and public affairs official. He was a chief advisor to EPA Administrator Lisa P. Jackson and a member of her senior management team.

Oster has nearly two decades of experience in senior-level communications positions in both the public and private sectors, including prior work in government, entertainment, organized labor, and the high-tech industry. Prior to the EPA, Oster served as executive vice president for global communications at the Motion Picture Association of America. He has also held senior communications positions at the Screen Actors Guild, Napster, and the American Film Institute, and is a former top communications aide to US Sen. Dianne Feinstein.

According to John Veihmeyer, KPMG chairman and CEO: “In the dynamic and challenging business environment that exists today, where the capital markets and our clients depend on our services and expertise more than ever, the impact and importance of strong, effective communications has never been greater.”