The calculated distance (air line) between Phnom Penh and Thủ Dầu Một is approximately 124 miles respectively 200 kilometers.
By car or train, the actual journey to Thủ Dầu Một is certainly longer, as only the direct route (as the crow flies) between Phnom Penh and Thủ Dầu Một has been calculated here.
Air line (approximately)
200 kilometers
108 nautical miles