The Soyuz-2.1v, GRAU index 14A15, known earlier in development as the Soyuz-1, is a Russian expendable launch vehicle. It is a heavily modified derivative of the Soyuz-2.1b, and is a member of the R-7 family of rockets. It is built by TsSKB Progress, at Samara in Russia. Launches are conducted from existing facilities at the Plesetsk Cosmodrome in Northwest Russia, with pads also available at the Baikonur Cosmodrome in Kazakhstan, and new facilities at the Vostochny Cosmodrome in Eastern Russia.

Soyuz-2 is a modernised version of the Soviet Soyuz rocket. In its basic form, it is a three-stage launch vehicle for placing payloads into low Earth orbit. Compared to the previous versions of the Soyuz, the first-stage boosters and two core stages feature uprated engines with improved injection systems. Digital flight control and telemetry systems allow the rocket to be launched from a fixed launch platform, whereas the launch platforms for earlier Soyuz rockets had to be rotated as the rocket could not perform a roll to change its heading in flight.