The calculated distance (air line) between Vaudreuil-Dorion and Longueuil is approximately 28 miles respectively 46 kilometers.
By car or train, the actual journey to Longueuil is certainly longer, as only the direct route (as the crow flies) between Vaudreuil-Dorion and Longueuil has been calculated here.
Air line (approximately)
46 kilometers
25 nautical miles