The calculated distance (air line) between Oberndorf bei Salzburg and Sankt Pölten is approximately 126 miles respectively 203 kilometers.
By car or train, the actual journey to Sankt Pölten is certainly longer, as only the direct route (as the crow flies) between Oberndorf bei Salzburg and Sankt Pölten has been calculated here.
Air line (approximately)
203 kilometers
109 nautical miles