The calculated distance (air line) between Saint-Quentin-en-Yvelines and Issy-les-Moulineaux is approximately 12 miles respectively 20 kilometers.
By car or train, the actual journey to Issy-les-Moulineaux is certainly longer, as only the direct route (as the crow flies) between Saint-Quentin-en-Yvelines and Issy-les-Moulineaux has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles