The calculated distance (air line) between L'Haÿ-les-Roses and Saint-Quentin-en-Yvelines is approximately 15 miles respectively 23 kilometers.
By car or train, the actual journey to Saint-Quentin-en-Yvelines is certainly longer, as only the direct route (as the crow flies) between L'Haÿ-les-Roses and Saint-Quentin-en-Yvelines has been calculated here.
Air line (approximately)
23 kilometers
13 nautical miles