S41 may refer to:
Aircraft Blériot-SPAD S.41, a French fighter aircraft Short S.41, a British biplane floatplane Sikorsky S-41, an American flying boat
Rail and transit S41 (Berlin), an S-Bahn line in Germany S41 (Long Island bus), United States S41 (ZVV), a line of the Zurich S-Bahn, Switzerland S41, a rush-hour line of Lucerne S-Bahn, Switzerland
Submarines , of the Argentine Navy
, of the Royal Navy , of the Indian Navy , of the United States Navy
Music Sum 41, a Canadian punk rock band
Other uses New Jersey Route 73, designated Route S41 until 1953 S41: In case of fire and/or explosion do not breathe fumes, a safety phrase Sulfur-41, an isotope of sulfur Xhosa language S41, a postcode district in Chesterfield, England