Martigny-les-Bains is a commune in the Vosges department in Lorraine in northeastern France.
It acquired its present name only in 1880s, before which it was called Martigny-lès-Lamarche. The modern name highlights the thermal springs and spa facilities which remain a defining feature of the place.
Inhabitants are called Octoduriens.
Martigny-les-Bains is positioned in the south-west of Lorraine and at the western end of the Vosges Plain, forty kilometres (twenty-five miles) to the south of the administrative centre of the arrondissement, Neufchâteau, approximately six kilometres (four miles) to the north-east of Lamarche, and twenty-two kilometres to the north of another noted spa town, Bourbonne-les-Bains ("Aquae borvonis" in Roman times).
The village occupies a sheltered plateau. On the higher ground forests of oak and beech alternate with conifer plantations. The village is protected by the topography from the worst extremes of wind and temperature.
The railway which since 1881 has provided a connection with Vittel and Contrexéville skirts the village on its north-western side. Some fifteen kilometres to the west the Autoroute A31 offers access to the autoroute network for the age of mass motorisation, while five kilometres to the east, roughly parallel with the autoroute and the railway line, the remnants of a Roman road provide evidence that the district has been much transited over many centuries.