London Thamesport (formerly just "Thamesport") was a small container seaport on the River Medway, serving the North Sea. It is located on the Isle of Grain, in the Medway unitary authority district of the English county of Kent. The area was formerly called Port Victoria. Since early 2020, Thamesport has ceased to operate as a container port, having been eclipsed by the new and much larger London Gateway container port on the Essex coast of the Thames Estuary.