Commodore Sir William James (1720-16 December 1783) was a notable British naval commander of the 18th century.

A poor Welsh miller's son, James ran away to sea in 1732 and by 1738 was commanding his own ship and serving in the West Indies. Nine years later, he joined the British East India Company (1747), and was appointed commodore of its marine forces four years later.

He is particularly associated with an action on 2 April 1755 when, commanding the Bombay Marine Ship Protector he attacked and destroyed the fortress of the notorious Moorish pirate Tollagee Angria at ?Severndroog ? (an English representation of the latter part of Janjeera Soowumdroog), in Concan , along the western coast of India, between Mumbai and Goa. (He had initially been instructed only to blockade the stronghold, but through his intimate knowledge of the rocky coastline was able to get close enough to blow up the fortress. Although the East India Company had spent considerable sums providing protection from piracy, he only received £100 in reward).

In February 1756, he supported the capture of Geriah by Colonel Robert Clive and Admiral Watson, and was active in numerous skirmishes against the French, helping to consolidate the British position in India.

He returned to England in 1759, settling in Eltham in south-east London, and later became chairman of the directors of the East India Company, a governor of Greenwich Hospital and a fellow of the Royal Society for his contribution to navigation. Created a baronet in 1778, he died of a stroke at his daughter's wedding in 1783, and, the following year, a folly, Severndroog Castle (designed by East India Company architect Richard Jupp), was built as a memorial to him by his wife, Lady James of Eltham, on nearby Shooter's Hill in south-east London.