The calculated distance (air line) between Niagara-on-the-Lake and Kitchener is approximately 73 miles respectively 117 kilometers.
By car or train, the actual journey to Kitchener is certainly longer, as only the direct route (as the crow flies) between Niagara-on-the-Lake and Kitchener has been calculated here.
Air line (approximately)
117 kilometers
63 nautical miles