The calculated distance (air line) between Kourou and Saint-Laurent-du-Maroni is approximately 98 miles respectively 158 kilometers.
By car or train, the actual journey to Saint-Laurent-du-Maroni is certainly longer, as only the direct route (as the crow flies) between Kourou and Saint-Laurent-du-Maroni has been calculated here.
Air line (approximately)
158 kilometers
85 nautical miles