S42 may refer to:
Aviation
edit- Blériot-SPAD S.42, a French biplane trainer aircraft
- Sikorsky S-42, an American flying boat
- Springer Municipal Airport, in Colfax County, New Mexico, United States
Rail and transit
edit- S42 (Berlin), a line of the Berlin S-Bah
- S42 (Long Island bus)
- S42 (New York City bus), serving Staten Island
Science
edit- S-42 (geodetic datum), used in Eastern Europe
- S42: During fumigation/spraying wear suitable respiratory equipment (appropriate wording to be specified by the manufacturer), a safety phrase
- Sulfur-42, an isotope of sulfur
Submarines
edit- ARA San Juan (S-42), of the Argentine Navy
- HMS Ursula (S42), of the Royal Navy
- INS Vagli (S42), of the Indian Navy
- USS S-42 (SS-153), a submarine of the United States Navy
Other uses
edit- IBM NetVista S42, a personal computer
- Siemens S42, a mobile phone
- Zulu language
- S42, a postcode district in Chesterfield, England