William Lyne, Australian politician, 13th Premier of New South Wales (b. 1844)
Sir William John Lyne KCMG (6 April 1844 – 3 August 1913) was an Australian politician who served as Premier of New South Wales from 1899 to 1901, and later as a federal cabinet minister under Edmund Barton and Alfred Deakin. He is best known as the subject of the "Hopetoun Blunder", unexpectedly being asked to serve as the first Prime Minister of Australia but failing to form a government.

Lyne was born in Van Diemen's Land, the son of a pastoral farmer. When he was 20, he and cousin took up a sheep station in North West Queensland. However, he moved back home after a few years and found work in local government. Lyne moved to New South Wales in 1875, buying a station near Albury and becoming prominent in community affairs. He was elected to the colonial Legislative Assembly in 1880, and first entered cabinet in 1885 under George Dibbs. He was a member of the Protectionist Party, and a major opponent of free-traders Henry Parkes and George Reid.

Lyne was elected leader of the Protectionists in 1895, and became Leader of the Opposition in New South Wales. He stood aside in 1898, but returned as leader the following year and became premier at the head of a coalition with the Labor Party. Lyne led an energetic and progressive government, instituting a number of major social reforms. He supported federation in principle, serving as a delegate to multiple constitutional conventions. However, he considered the draft constitution to be too unfavourable to New South Wales and supported the "no" vote at the 1898 and 1899 referendums.

In 1900, Lyne was asked by Lord Hopetoun (the incoming governor-general) to lead Australia's first national government. Hopetoun was relying on the precedent established at Canadian Confederation, where the premier of the largest colony became the prime minister of the new federation. However, Lyne had no support from leading federationists and was forced to relinquish the honour to Edmund Barton. Lyne became Minister for Home Affairs in Barton's government, and was later Minister for Trade and Customs and Treasurer under Alfred Deakin. Lyne opposed the formation of the new Commonwealth Liberal Party in 1909 and spent the rest of his career as a crossbencher, supporting Andrew Fisher's Labor government. He lost his seat at the 1913 election and died a few months later.