The calculated distance (air line) between Longjumeau and Marne La Vallée is approximately 19 miles respectively 30 kilometers.
By car or train, the actual journey to Marne La Vallée is certainly longer, as only the direct route (as the crow flies) between Longjumeau and Marne La Vallée has been calculated here.
Air line (approximately)
30 kilometers
16 nautical miles