Which river flows through London and reaches the North Sea?

The River Thames flows through London and reaches the North Sea.

The Thames rises at Thames Head in Gloucestershire and runs generally eastward across southern England. It passes through or beside towns including Oxford, Reading, Windsor, and London before entering the Thames Estuary and the North Sea.

The river has shaped London’s history, transport, trade, and defenses. Roman Londinium developed around a crossing point, and the tidal river later supported docks, warehouses, shipyards, and international commerce. London Bridge, Westminster Bridge, and Tower Bridge are among the structures associated with its urban course.

The Thames is tidal through central London, so its water level changes with the sea. It is often called England’s longest river, although the Severn is longer when measured by the usual source-to-mouth definition. The Thames Barrier, completed in 1982, protects much of London from tidal flooding and storm surges.