Which river flows through London and empties into the North Sea?

The River Thames flows through London and empties into the North Sea.

The Thames is England’s longest river entirely within England, running for about 346 kilometres from its source near Kemble in Gloucestershire to its estuary. It passes through or beside many important places, including Oxford, Reading, Windsor, and London, before reaching the North Sea.

London grew around a crossing point and harbor on the tidal lower Thames. The Romans founded Londinium near the river around AD 43, and the waterway later supported trade, shipbuilding, industry, and imperial connections. Bridges, docks, and riverside landmarks remain central to the capital’s identity.

The Thames is tidal as far upstream as Teddington Lock. Its estuary is much wider than the river through central London, and the Thames Barrier, completed in 1982, protects the capital from some storm-surge flooding. The river is sometimes confused with the Severn, which is Britain’s longest river but follows a different course.