Sir William Jones (28 September 1746 – 27 April 1794) was a British philologist, scholar and judge. Born in Westminster to the Welsh mathematician William Jones, he moved to the Bengal Presidency where Jones served as a puisne judge on the Supreme Court of Judicature at Fort William and also became a scholar of ancient Indian history. He is known for being one of the earliest scholars after father Gaston-Laurent Coeurdoux to assert the kinship of the Indo-European languages. Jones also founded the Asiatic Society in Calcutta in 1784.

William Jones was born in London; his father William Jones (1675–1749) was a mathematician from Anglesey in Wales, noted for introducing the mathematical use of the symbol π. The young William Jones was a linguistic prodigy, who in addition to his native languages English and Welsh, learned Greek, Latin, Persian, Arabic, Hebrew and the basics of Chinese writing at an early age. By the end of his life, he knew eight languages with critical thoroughness.

Jones's father died when he was aged three, and his mother Mary Nix Jones raised him. He was sent to Harrow School in September 1753 and then went on to University College, Oxford. He graduated there in 1768 and became M.A. in 1773. Financially constrained, he took a position tutoring the seven-year-old Lord Althorp, son of Earl Spencer. For the next six years, he worked as a tutor and translator. During this time he published in 1770 Histoire de Nader Chah (History of Nader Shah), a French translation of a work originally written in Persian by Mirza Mehdi Khan Astarabadi. This was done at the request of King Christian VII of Denmark: he had visited Jones, who by the age of 23 had already acquired a reputation as an orientalist, and in appreciation of his work he was granted membership in the Royal Danish Academy of Sciences and Letters. This would be the first of his numerous works on Persia, Anatolia, and the Middle East in general.

In 1770, Jones joined the Middle Temple and studied law for three years, a preliminary to his life-work in India. He was elected a Fellow of the Royal Society on 30 April 1772. In 1773, he was elected a member of The Club, of which he became president in 1780. He spent some time as a circuit judge in Wales, and then became involved in politics: he made a fruitless attempt to resolve the American Revolution in concert with Benjamin Franklin in Paris, and ran for the post of Member of Parliament from Oxford in the general election of 1780, but was unsuccessful.

Jones was a radical political thinker, and a friend of American independence. His work, The principles of government; in a dialogue between a scholar and a peasant (1783), was the subject of a trial for seditious libel (known as the Case of the Dean of St Asaph) after it was reprinted by his brother-in-law William Davies Shipley.

He was appointed puisne judge to the Supreme Court of Judicature at Fort William in Calcutta, Bengal, on 4 March 1783, and on 20 March he was knighted. In April 1783 he married Anna Maria Shipley, the eldest daughter of Jonathan Shipley, Bishop of Llandaff and Bishop of St Asaph. Anna Maria used her artistic skills to help Jones document life in India. On 25 September 1783, he arrived in Calcutta.

In the Subcontinent he was entranced by Indian culture, an as-yet untouched field in European scholarship, and on 15 January 1784 he founded the Asiatic Society in Calcutta. He studied the Vedas with Rāmalocana, a pandit teaching at the Hindu University of Nadiya, becoming a proficient Sanskritist. Jones kept up a ten-year correspondence on the topic of jyotisa or Hindu astronomy with fellow orientalist Samuel Davis. He learnt the ancient concept of Hindu Laws from Pandits.

Over the next ten years, he produced a flood of works on India, launching the modern study of the subcontinent in virtually every social science. He also wrote on the Hindu and Muslim laws, music, literature, botany, and geography, and made the first English translations of several important works of Indian literature.