John Philip McCarthy AO (born 29 November 1942) is a former Australian diplomat.

Born in Washington, D.C., McCarthy was educated at Downside School, Somerset, in England and studied at Jesus College, Cambridge.

He received a Master of Arts and a Bachelor of Laws degree from Cambridge University.

He worked with the New York City Law Firm of Shearman & Sterling from 1966 to 1967 and joined the Department of External Affairs in Canberra in 1968.

[2] McCarthy was senior private secretary to the Australian Minister for Foreign Affairs, Andrew Peacock, between December 1978 and November 1980.