Soyuz-V (Russian: Союз-В meaning Union-V) or Soyuz 11K (Russian: Союз 11К), sometimes known in the west as Soyuz-C, was a proposed Soviet spacecraft, which was designed for use as a fuel tanker.

It would have been used to refuel other spacecraft, particularly the Soyuz 9K orbital tug.

It was part of the Soyuz A-B-V complex for human circumlunar spaceflight.

Following launch, it would have docked with the NO docking module of a waiting Soyuz 9K, and transferred over 7,000 kilograms (15,000 lb) of fuel into the tug.

This article about one or more spacecraft of the Soviet Union is a stub.