Rear Admiral Peter Ross Sinclair, (born 16 November 1934) is a retired senior officer of the Royal Australian Navy who served as the 35th Governor of New South Wales from 8 August 1990 to 1 March 1996.
Born in Manly, New South Wales, he was educated North Sydney Boys High School before joining the navy through the Royal Australian Naval College.
Over a 41-year career, Sinclair saw active service in Korea, Malaysia, Vietnam and in relief operations following Cyclone Tracy, and commanded the naval base HMAS Penguin.
He later rose to high command, serving as Director of Naval Plans and as chief project officer during the establishment of the tri-service Australian Defence Force Academy, and then serving as its first commandant.
In 1987 he was appointed Flag Officer Commanding HM Australian Fleet, which was redesignated as Maritime Commander Australia the following year.
In 1989 he was appointed as Deputy Chief of the Naval Staff but served only briefly until his retirement later that year.
When his friend and navy colleague, Sir David Martin, resigned his commission as Governor of New South Wales in August 1990 due to an advancing medical condition, Sinclair was appointed to succeed him.
He retired in 1996 while controversy of Carr's proposed changes of the Governor's role emerged in regard to his successor.