S73

S73 may refer to:

Aircraft

 * Bernard S-73, a French racing monoplane
 * Savoia-Marchetti S.73, an Italian airliner
 * Sikorsky S-73, an American helicopter proposal

Submarines

 * HMCS Onondaga (S73), of the Royal Canadian Navy
 * INS Arihant (S73), of the Indian Navy
 * INS Rachav (S73), of the Israeli Navy

Other uses

 * County Route S73 (Bergen County, New Jersey)
 * S73, a postcode district for Barnsley, England