Louis-Hippolyte Lafontaine, Canadian lawyer and politician, 2nd Premier of Canada East (d. 1864)
Sir Louis-Hippolyte Ménard dit La Fontaine, 1st Baronet, KCMG (October 4, 1807 – February 26, 1864) was a Canadian politician who served as the first Premier of the United Province of Canada and the first head of a responsible government in Canada. He was born in Boucherville, Lower Canada in 1807. A jurist and statesman, La Fontaine was first elected to the Legislative Assembly of Lower Canada in 1830. He was a supporter of Papineau and member of the Parti canadien (later the Parti patriote). After the severe consequences of the Rebellions of 1837 against the British authorities, he advocated political reforms within the new Union regime of 1841.

Under this Union of the two Canadas he worked with Robert Baldwin in the formation of a party of Upper and Lower Canadian liberal reformers. He and Baldwin formed a government in 1842 but resigned in 1843. In 1848 he was asked by the Governor-General, Lord Elgin, to form the first administration under the new policy of responsible government. The La Fontaine-Baldwin government, formed on March 11, battled for the restoration of the official status of the French language, which was abolished with the Union Act, and the principles of responsible government and the double-majority in the voting of bills.

While Baldwin was reforming Canada West (Upper Canada), La Fontaine passed bills to abolish the tenure seigneuriale (seigneurial system) and grant amnesty to the leaders of the rebellions in Lower Canada who had been exiled. The bill passed, but it was not accepted by the loyalists of Canada East who protested violently and burned down the Parliament in Montreal.

La Fontaine retired to private life in 1851 but was appointed Chief Justice of Canada East in 1853. In 1854 he was created a baronet by Queen Victoria and a knight commander in the pontifical Order of St. Sylvester by Pope Pius IX in 1855.

His last name is often written in one word (Lafontaine or LaFontaine); his own signature was one word.