Oncourt () is a former commune in the Vosges department in northeastern France. On 1 January 2016, it was merged into the new commune Capavenir-Vosges, which was renamed Thaon-les-Vosges effective 2022. Inhabitants are called Oncourtois.
The village is positioned some to the west of the village of Thaon-les-Vosges, and crossed by the little river , itself a tributary of the Moselle.
, actor and animator with a French television providers, spent a part of his childhood and adolescence at Oncourt.