The calculated distance (air line) between Saint-Quentin-en-Yvelines and Antony is approximately 13 miles respectively 20 kilometers.
By car or train, the actual journey to Antony is certainly longer, as only the direct route (as the crow flies) between Saint-Quentin-en-Yvelines and Antony has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles