S31
# S31

S31 may refer to:

## Aviation

* Blériot-SPAD S.31, a French racing aircraft
* Letov Š-31, a Czechoslovakian fighter aircraft
* Lopez Island Airport, in San Juan County, Washington, United States
* Short S.31, a British bomber prototype
* Sikorsky S-31, an American sesquiplane

## Naval vessels

* ARA Salta (S-31), a submarine of the Argentine Navy
* Brazilian submarine Tamoio (S-31)
* HMS Vengeance (S31), a submarine of the Royal Navy
* SMS S31 (1913), a torpedo boat of the Imperial German Navy
* Spanish submarine Almirante García de los Reyes (S31)
* USS S-31 (SS-136), a submarine of the United States Navy

## Rail and transit

* S31 (Long Island bus)
* Warabitai Station, a closed station in Oshamambe, Hokkaido, Japan
* S31, a line of the Bern S-Bahn, in Switzerland
* S31, a line of the Hamburg S-Bahn, in Germany
* S31, a line of the Karlsruhe Stadtbahn, in Germany

## Roads

* Mehran Highway, in Sindh, Pakistan
* County Route S31 (California), United States
* County Route S31 (Bergen County, New Jersey), United States
* U.S. Route 206, partially numbered New Jersey Route S31 until 1953

## Other uses

* Sulfur-31, an isotope of sulfur
