The calculated distance (air line) between Yonge-Eglinton and Oshawa is approximately 31 miles respectively 49 kilometers.
By car or train, the actual journey to Oshawa is certainly longer, as only the direct route (as the crow flies) between Yonge-Eglinton and Oshawa has been calculated here.
Air line (approximately)
49 kilometers
27 nautical miles