Nassau William Senior was an English economist and author. He was born at Compton Beauchamp, Berkshire, September 26, 1790. He was educated at Oxford, receiving a B.A. (1812) and an M.A. (1815). He was called to the bar in 1819, but his life's work was in the field of political economy. Senior's father, the Rev. John Raven Senior, was the vicar of Durnford Wiltshire, and the younger Senior came to believe that charity in his father's parish was often misdirected. Early in his career, he resolved to reform the English poor law.

Senior became a member of the Political Economy Club in 1823, and he was chosen as the first professor of political economy at Oxford in 1825. Many of his lectures were published which helped to establish his reputation in England and in France. In 1830, he prepared a report on trade combinations for Lord Melbourne, the home secretary. The report was the substance of Historical and Philosophical Essays published in 1865. In 1833, he was appointed to the poor-law commission and was the author of a report which established the poor-law of 1834. Senior served on several royal commissions dealing with factories and trade.He had a particular interest in the state of affairs in Ireland. He traveled there often and wrote pamphlets, letters, and reviews discussing the critical problems in that country. In 1831, he published A Letter to Lord Howick, on a Legal Provision for the Irish Poor: Commutation of Tithes, and a Provision for the Irish Roman Catholic Clergy.

Senior was in Paris in May 1848 when an attack was made on the national assembly. At that time, Senior began a practice which he found useful in many of his writings. He began to keep a full journal and to record conversations with prominent persons. His own observations and opinions formed part of the narrative. He made use of this convention in his travel diaries written during trips to Greece, Turkey, Egypt, Malta, and Ireland. To avoid any misrepresentation, he sometimes allowed the original speakers to revise the writings. Senior's daughter, Mary Charlotte Mair, (later Mrs. C. J. Simpson), published parts of his journals after his death. Titles include: A Journal Kept in Turkey and Greece (1859), Journals, Conversations and Essays Relating to Ireland (1868), Journals Kept in France and Italy from 1848 to 1852 (1871), and Conversations with Distinguished Persons During the Second Empire (1880).

Nassau William Senior died in Kensington, June 4, 1864.