Sir William Blackstone, (July 10,1723 - February 14,1780) was an English jurist and professor who produced the historical treatise on the common law called Commentaries on the Laws of England, first published in four volumes over 1765–1769.

Blackstone received his education at Pembroke College, Oxford. In 1743 he became a fellow of All Souls College, Oxford, and he was called to the bar as a barrister in 1746. After practising in the courts of Westminster for several years, he returned to Oxford in 1758 when another lawyer, Charles Viner , established an endowed chair at the university for a lecturer in law. Viner's endowed chair became known as the Vinerian professorship , and it continues to exist to the present day.

In addition to the Commentaries, Blackstone published treatises on Magna Carta and the Charter of the Forest . In 1761 he won election as a Member of Parliament for Hindon and "took the silk" as a king's counsel.

Blackstone and his work occasionally appear in literature. For example, Blackstone receives mention in Herman Melville's Moby-Dick.

US courts frequently quote Blackstone's Commentaries on the Laws of England as the definitive pre-Revolutionary War source of common law; in particular, the United States Supreme Court quotes from Blackstone's work whenever they wish to engage in historical discussion that goes back that far, or further (for example, when discussing the intent of the Framers of the Constitution). US and other common law courts mention with strong approval Blackstone's formulation: "Better that ten guilty persons escape than that one innocent suffer" -- although he did not first express the principle.