Philip Sandeman Ziegler is a British biographer and historian. Originally intending to be a novelist, he began a career as biographer with his life of Talleyrand's lover, the Duchess of Dino. He was editor in chief at Collins from 1979-80. He has written in various journals and newspapers including The Spectator, The Listener, The Times, The Daily Telegraph and History Today.

Ziegler was educated at St Cyprian's School, Eastbourne, and went with the school when it merged with Summer Fields School, Oxford. He was afterwards at Eton College and New College, Oxford. He earned a degree in Jurisprudence with highest honours before joining the British Foreign Service, in which he served in Laos, Pretoria and Bogotá, as well as with the Delegation to NATO in Paris.