VCO

VCO may refer to:

Military

 * Veterinary Corps Officer, see Veterinary corps (disambiguation)
 * Viceroy's commissioned officer, British Indian Army role (1885–1947)

Technology

 * Voltage-controlled oscillator, an electronic device
 * Voice Carry Over, a telecommunications relay service
 * Akatsuki (spacecraft), or the Venus Climate Orbiter
 * Virtual Central Office, in Open Platform for NFV network-function virtualization software

Other uses

 * Voyage Century Online, a nautically themed, free-to-play, massively multiplayer online role-playing game
 * Vice Commodore, an elected yacht club committee member
 * VCO SA, the joint-stock company, and a distributor of Volcano clothing brand