V1
V1, V01 or V-1 can refer to version one (for anything) (e.g., see version control)
V1, V01 or V-1 may also refer to:

In aircraft
V-1 flying bomb, a World War II German weapon
V1 speed, the maximum speed at which an aircraft pilot may abort a takeoff without causing a runway overrun
Vultee V-1, an American single-engine airliner of the 1930s
Fokker V.1, a German parasol monoplane experimental fighter prototype, built in 1916
The first prototype/experimental (Versuchs) airframe of nearly any German WW II-era military aircraft

Vessels
V1-class destroyer, a German World War I destroyer class
USS V-1, 1924–1931 designation of the USS Barracuda (SS-163), first of the US "V-boat" series of submarines
V1, a rudderless single-paddler outrigger canoe

In medicine
V1, the primary visual cortex
V1, the ophthalmic nerve, first division of the trigeminal nerve
V1, one of six precordial leads in electrocardiography

In astronomy
V1, or Hubble variable number one is the name given to a historically important Cepheid variable star in the Andromeda Galaxy

Other uses
Base form (V1) of an English verb
ATC code V01 Allergens, a subgroup of the Anatomical Therapeutic Chemical Classification System
V1 (classification), a Paralympic archery classification for people with visual disabilities
LNER Class V1, a 1930–1939 British 2-6-2 tank engine class
NER Class V1, a class of British steam locomotives officially classified V/09, but classified V1 in some sources
Nikon 1 V1, a camera
V1 Gallery, in Copenhagenany
ITU-T V.1, a telecommunication recommendation
V1, a visual query language for property graphs
Z1 (computer), previously known as V1
V1 (film), a 2019 Indian film

See also
VI (disambiguation) (letter "i" as opposed to number "1")