The calculated distance (air line) between Sainte-Anne-des-Plaines and Longueuil is approximately 24 miles respectively 39 kilometers.
By car or train, the actual journey to Longueuil is certainly longer, as only the direct route (as the crow flies) between Sainte-Anne-des-Plaines and Longueuil has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles