The Battle of Deorham or Dyrham is fought in 577 between the West Saxons under Ceawlin and Cuthwine and the Britons of the West Country.

The location, Deorham, is usually taken to refer to Dyrham in South Gloucestershire.

The battle is a major victory for the West Saxons, who take three important cities, Glevum (Gloucester), Corinium (Cirencester) and Aquae Sulis (Bath).

The battle is known exclusively from the Anglo-Saxon Chronicle, which gives few details, but it is thought to have been a major engagement.