4V

4V or 4-V may refer to:


 * 4V, abbreviation for 4 volts
 * 4V, abbreviation for 4-valve engine
 * 4V, IATA code for Birdy Airlines
 * Venera 4V-2 spacecraft
 * Sun-4v, a model of Sun-4 workstation
 * 6AL-4V, a type of titanium alloy
 * 4V, a model of Toyota V engine
 * 4V, abbreviation for QuatroV - TV Show
 * 4V, the production code for the 1977 Doctor Who serial Horror of Fang Rock
 * 4V: an ITU prefix for Haiti