Old Father Thames

Thames
River
The Thames in London
Country	England
Counties	Gloucestershire, Wiltshire, Oxfordshire, Berkshire, Buckinghamshire, Surrey, Middlesex, London, Kent, Essex
Towns/Cities	Cricklade, Lechlade, Oxford, Abingdon, Wallingford, Reading, Henley-on-Thames, Marlow, Maidenhead, Windsor, Staines-upon-Thames, Walton-on-Thames, Kingston upon Thames, Teddington, Richmond, London, London
Source
- location	Thames Head, Gloucestershire, UK
- elevation	110 m (361 ft)
- coordinates	51°41′39″N 2°01′47″W / 51.694262°N 2.029724°W / 51.694262; -2.029724
Mouth	Thames Estuary, North Sea
- location	Southend-on-Sea, Essex, UK
- elevation	0 m (0 ft)
- coordinates	51°29′56″N 0°36′31″E / 51.4989°N 0.6087°E / 51.4989; 0.6087Coordinates: 51°29′56″N 0°36′31″E / 51.4989°N 0.6087°E / 51.4989; 0.6087
Length	346 km (215 mi)
Basin	12,935 km2 (4,994 sq mi)
Discharge	for London
- average	65.8 m3/s (2,324 cu ft/s)
- max	370 m3/s (13,066 cu ft/s)
Discharge elsewhere (average)
- entering Oxford	17.6 m3/s (622 cu ft/s)
- leaving Oxford	24.8 m3/s (876 cu ft/s)
- Reading	39.7 m3/s (1,402 cu ft/s)
- Windsor	59.3 m3/s (2,094 cu ft/s)
Map of the Thames within southern England

The River Thames (/tɛmz/ TEMZ) is a river that flows through southern England, most notably through London. At 215 miles (346 km), it is the longest river entirely in England and the second longest in the United Kingdom, after the River Severn. It also flows through Oxford (where it is called Isis), Reading, Henley-on-Thames and Windsor. The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock. It rises at Thames Head in Gloucestershire, and flows into the North Sea via the Thames Estuary. The Thames drains the whole of Greater London.

Its tidal section, reaching up to Teddington Lock, includes most of its London stretch and has a rise and fall of 7 metres (23 ft). Running through some of the driest parts of mainland Britain and heavily abstracted for drinking water, the Thames' discharge is low considering its length and breadth: the Severn has a discharge almost twice as large on average despite having a smaller drainage basin. In Scotland, the Tay achieves more than double the average discharge from a drainage basin that is 60% smaller.