S44

S44 may refer to:
 * S44 (New York City bus) serving Staten Island
 * S44 (St. Gallen S-Bahn), a railway service in Switzerland
 * GER Class S44, a British steam locomotive
 * INS Shishumar (S44), a submarine of the Indian Navy
 * New Jersey Route 324, designated Route S44 until 1953
 * Sulfur-44, an isotope of sulfur
 * USS S-44 (SS-155), a submarine of the United States Navy
 * S44, a postcode district in Chesterfield, England