Ouanne (French pronunciation: [wan]) is a commune in the Yonne department in Bourgogne-Franche-Comté in north-central France, in the natural region of Forterre.

Ouanne existed in Gallo-Roman times under the name of Odouna or Oduna. A Roman way carried out in Auxerre. The ancient station of Ouanne is known from a marble fragment from the 3rd century, preserved at the museum of Autun. The marble indicates the distances on the Roman road from Auxerre to Entrains-sur-Nohain. The armies of Pippin the Younger passed along this road.

In 1790, Ouanne became the chief town of its canton, but the number of cantons was subsequently reduced and the village became attached to Courson-les-Carrières. In December 1972, Ouanne was merged with Merry-Sec and Chastenay. In January 1980, Merry-Sec became a separate commune again.

The river Ouanne, a 84 km (52 mi) long right tributary of the Loing, has its source in the commune.

Inhabitants of Ouanne are known as Ouannais.

Historical population

Year Pop. ±% p.a. 1793 1,019 —     1851 1,239 +0.34% 1881 1,054 −0.54% 1901 991 −0.31% 1931 720 −1.06% 1968 766 +0.17% 1975 649 −2.34%	Year Pop. ±% p.a. 1982 589 −1.38% 1990 627 +0.78% 1999 661 +0.59% 2007 698 +0.68% 2012 635 −1.87% 2017 606 −0.93%
Source: EHESS and INSEE (1968-2017)

• Notre-Dame Church (15th-16th centuries), blazing style, entirely arched
• Source de l'Ouanne (built in 1867), close to the laundrette
• Castle of the Mines (16th century)

• René Lepage de Ste-Claire

• Communes of the Yonne department