The calculated distance (air line) between Saint-Quentin-Fallavier and Montpellier is approximately 153 miles respectively 246 kilometers.
By car or train, the actual journey to Montpellier is certainly longer, as only the direct route (as the crow flies) between Saint-Quentin-Fallavier and Montpellier has been calculated here.
Air line (approximately)
246 kilometers
133 nautical miles