The calculated distance (air line) between Romilly-sur-Seine and Marne La Vallée is approximately 54 miles respectively 87 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 Romilly-sur-Seine and Marne La Vallée has been calculated here.
Air line (approximately)
87 kilometers
47 nautical miles