Baron Harlech, of Harlech in the County of Merioneth, is a title in the Peerage of the United Kingdom. It was created in 1876 for the Conservative politician John Ormsby-Gore, with remainder to his younger brother William. He had previously represented Carnarvon and North Shropshire in the House of Commons. Ormsby-Gore was the eldest son of William Ormsby-Gore, Member of Parliament for County Leitrim, Carnarvon and North Shropshire, and the great-great-great-grandson of William Gore, third and youngest son of Sir Arthur Gore, 1st Baronet, of Newtown, second son of Sir Paul Gore, 1st Baronet, of Magharabag, whose eldest son Paul was the grandfather of Arthur Gore, 1st Earl of Arran.

William David Ormsby-Gore, 5th Baron Harlech, known as David Ormsby-Gore until June 1961 and as Sir David Ormsby-Gore from then until February 1964, was a British diplomat and Conservative politician.