The River Thame (pronounced to rhyme with 'tame') is a river in southern England. It is a tributary of the larger and better-known River Thames and should not be confused with it by the similarity of names.

The general course of the River Thame is north-east to south-west and the distance from its source to the River Thames is about 40 miles (65km). It flows through the English counties of Buckinghamshire and Oxfordshire.

The River Thame's source is several small streams which rise in the Vale of Aylesbury on the north side of the Chiltern Hills. These streams converge north-east of Aylesbury, the county town of Buckinghamshire. Aylesbury played an important role in the English Civil War when John Hampden (the town's Member of Parliament) defended Aylesbury at the Battle of Holman's Bridge in 1642.

The streams converge very close to the new village of Watermead. After leaving Watermead, the River Thame flows through farmland passing the small villages of Nether Winchendon and Chearsley before reaching the market town of Thame with which it shares its name. Thame is about 15 miles east of Oxford and grew from a Anglo Saxon settlement beside the river. In Anglo Saxon times, Thame was in the diocese of Dorchester (see below).

From Thame, the River Thame swings southward and after passing the villages of Great Milton and Stadhampton , its valley widens out.

The River Thame then reaches the small town of Dorchester, Oxfordshire (not to be confused with Dorchester, Dorset). There was a Romano-British settlement here and the town itself is of Anglo Saxon origin. There was a Saxon cathedral here, later superceded by Dorchester Abbey which is preserved.

A mile south of Dorchester, the River Thame flows into the River Thames.

See also

• Rivers of Great Britain
• River Tame