S25

__NOTOC__S25 can refer to:
* , a safety phrase in chemistry
* S25 (Berlin), a line on the Berlin S-Bahn
* S25 postcode, covering areas south of Rotherham
* S25 (Long Island bus)
* British NVC community S25, a swamps and tall-herb fens community in the British National Vegetation Classification system
* County Route S25 (California)
* County Route S25 (New Jersey), a county route in Bergen County
* Siemens S25, a Siemens mobile phone

S-25 may refer to:
* S-25 Berkut, a Soviet surface-to-air missile system
* S-25 rocket, an air-to-ground rocket
* USS S-25 (SS-130), a first-group (S-1 or "Holland") S-class submarine of the United States Navy

S.25 may refer to :
* , a U.S. Senate bill
* Short S.25 Sunderland, a 1937 flying boat patrol bomber developed for the Royal Air Force