Frank Henry Corner CMG (17 May 1920 – 27 August 2014) was a New Zealand diplomat. Corner served as New Zealand's Ambassador to the United Nations and the United States, before becoming New Zealand's third Permanent Secretary of Foreign Affairs (1973–1980).
Born in Napier, New Zealand, Corner was educated at Napier Boys' High School and Victoria University of Wellington, where he graduated in 1942 with a Master of Arts (First Class) in history, under the guidance of Professor J.C. Beaglehole.
Corner joined the Ministry of Foreign Affairs in 1943, being recruited as one of its earliest foreign policy officers by then Secretary Alister McIntosh, who was in the process of building a professional foreign service. In his first years of service, he was seconded to the staff of H. V. Evatt, Australia's outspoken Foreign Minister. He was closely involved in drafting Evatt's speeches which defined an era known as "small power rampant". On his return he worked closely with Prime Minister Peter Fraser as he developed a more distinctly New Zealand position within the framework of the Commonwealth. He was New Zealand's political officer (policy adviser) at the Paris Peace Talks.
Corner was posted first to Washington in 1948, as First Secretary, where he was involved in the negotiation and signature of the ANZUS Treaty and the Japanese Peace Settlement. In 1952 he was appointed Deputy High Commissioner in London, and was in London during the Suez crisis when New Zealand found itself torn in its loyalties between its new friend and protector (the US) and its "mother country", Britain. In 1958, Corner returned to New Zealand as Deputy Secretary of Foreign Affairs.
In 1961, Corner became New Zealand's Ambassador to the United Nations, where he chaired the Trusteeship Council for two years, and served on the United Nations Security Council. Corner was the leading proponent of decolonisation of Pacific territories under New Zealand control. Corner provided the leading intellectual arguments in favour of decolonisation of Tokelau, the Cook Islands, Niue, and Western Samoa.