The calculated distance (air line) between Fontaine-l'Évêque and Mouscron is approximately 54 miles respectively 87 kilometers.
By car or train, the actual journey to Mouscron is certainly longer, as only the direct route (as the crow flies) between Fontaine-l'Évêque and Mouscron has been calculated here.
Air line (approximately)
87 kilometers
47 nautical miles