Guillaume Henri Dufour (15 September 1787 14 July 1875) was a Swiss military officer, structural engineer and topographer. He served under Napoleon I and held the Swiss office of General four times in his career, firstly in 1847 when he led the Swiss Confederation forces to victory against the Sonderbund. In 1864 Dufour presided over the First Geneva Convention which established the International Red Cross. He was founder and president (1838 to 1865) of the Swiss Federal Office of Topography.

The Sonderbund War (German: Sonderbundskrieg, French: Guerre du Sonderbund, Italian: Guerra del Sonderbund) of November 1847 was a civil war in Switzerland, then still a relatively loose confederacy of cantons. It ensued after seven Catholic cantons formed the Sonderbund ("separate alliance") in 1845 to protect their interests against a centralization of power. The war concluded with the defeat of the Sonderbund. It resulted in the emergence of Switzerland as a federal state, concluding the period of political "restoration and regeneration" in Switzerland.The Sonderbund consisted of the cantons of Lucerne, Fribourg, Valais, Uri, Schwyz, Unterwalden and Zug, all predominantly Catholic and governed by conservative administrations. The cantons of Ticino and Solothurn, also predominantly Catholic but governed by liberal administrations, did not join the alliance.

After the Tagsatzung (Federal Diet) declared the Sonderbund unconstitutional (October 1847) and ordered it dissolved by force, General Guillaume Henri Dufour led the federal army of 100,000 and defeated the Sonderbund forces under Johann Ulrich von Salis-Soglio in a campaign that lasted only a few weeks, from November 3 to November 29, and claimed fewer than a hundred lives. Dufour ordered his troops to care for the injured, anticipating the formation of the Red Cross in which he participated a few years later. Major actions were fought at Fribourg, Geltwil (12 November), Lunnern, Lucerne, and finally at Gisikon (23 November), Meierskappel, and Schüpfheim, after which Lucerne capitulated on 24 November. The rest of the Sonderbund surrendered without armed resistance in the subsequent weeks.