Aroncey is located some 12 km north of Arnay-le-Duc and some 20 km east by south east of Saulieu. Access to the commune is by the D16 road from Allerey in the south passing though the village and continuing north-east to Thoisy-le-Désert. The D36 also goes from Allerey north through the western part of the commune and continuing to Beurey-Bauguay. The D115A links the village to the D36. Apart from the village there are also the hamlets of Juilly, Laneau, and Avincey. The commune is mostly farmland with a large forest in the south (Bois des Bates) and small forests scattered through the commune.
In 2009 the commune had 214 inhabitants. The evolution of the number of inhabitants is known from the population censuses conducted in the commune since 1793. From the 21st century, a census of communes with fewer than 10,000 inhabitants is held every five years, unlike larger towns that have a sample survey every year.[Note 1]
^At the beginning of the 21st century, the methods of identification have been modified by Law No. 2002-276 of 27 February 2002, the so-called "law of local democracy" and in particular Title V "census operations" allows, after a transitional period running from 2004 to 2008, the annual publication of the legal population of the different French administrative districts. For communes with a population greater than 10,000 inhabitants, a sample survey is conducted annually, the entire territory of these communes is taken into account at the end of the period of five years. The first "legal population" after 1999 under this new law came into force in 1 January 2009 and was based on the census of 2006.