Ollans is located in the department of Doubs, bordering the Haute-Saone, in the canton of Marchal and 30 km northeast of Besançon.
The first cadastre of the municipality of Ollans date of 1807. Surrounded by common Cendrey, Avilley, Maussan and Larians, its total area is 231 ha, 30 ha of forests. Located along the Ognon substantially in the middle of two large meanders in a pleasant green setting, Ollans houses spread over the side of a gentle hill that slopes down to the River.
Ollans, if one believes the old, comes from the Celtic "ol" (curvature) and "year" (river), the name would imply: in a river bend. Over the centuries the spelling has changed: Oslans (1218), Osllans (1239), Oyllans (1243), Ollans (1259), Olan (1421). Ollans made its appearance in history in 1243.