Philip S. Aiken (born 9 January 1949, in Sydney) is an Australian business executive. Aiken holds a Bachelor of Engineering degree in chemical engineering from University of Sydney, and has attended the Advanced Management Program from Harvard Business School. Aiken was formerly Group President of BHP Billiton's energy business, and an executive director of BTR plc. He held senior positions in BOC Group, and was also a senior advisor to Macquarie Capital (Europe). He also served as the chairman of Robert Walters from 2007 to 2012.