Frederic William Maitland (28 May 1850 – 19 December 1906) was an English jurist and historian, generally regarded as the modern father of English legal history.

He was the son of John Gorham Maitland (1818–1863), and was educated at Eton and Trinity College, Cambridge, being bracketed at the head of the moral sciences tripos of 1872, and winning a Whewell scholarship for international law.

He was called to the bar (Lincoln's Inn) in 1876, and became a competent equity lawyer and conveyancer, but finally devoted himself to comparative jurisprudence and especially the history of English law. In 1884 he was appointed reader in English law at Cambridge, and in 1888 became Downing professor of the laws of England. Despite his generally poor health, his intellectual grasp and wide knowledge and research gradually made him famous as a jurist and historian.

He edited many volumes for the Selden Society, including Select Pleas for the Crown, 1200–1225 and Select Pleas in Manorial Courts and The Court Baron. His principal works include:
Gloucester Pleas (1884)
Justice and Police (1885)
Bracton's Note-Book (1887) (Reissued by Cambridge University Press, 2010. ISBN 978-1-108-01031-3)
History of English Law before the Time of Edward I (with Sir Frederick Pollock, 1895; new ed. 1898; see also his article "English Law" in the Encyclopædia Britannica. Reissued by Cambridge University Press, 2010. ISBN 978-1-108-01807-4)
Domesday Book and Beyond (1897)
Township and Borough (1898)
Canon Law in England (1898)
English Law and the Renaissance (1901)
Charters of the Borough of Cambridge (1901) (Reissued by Cambridge University Press, 2010. ISBN 978-1-108-01043-6)
Life of Leslie Stephen (1906).

He also made important contributions to the Cambridge Modern History, the English Historical Review, the Law Quarterly Review, Harvard Law Review and other publications. Maitland delivered the Ford Lectures in 1897.
Posthumous publications by his students, editing their lecture notes based on his lectures, include The Constitutional History of England, Equity, and The Forms of Action at Common Law.
His written style was elegant and lively. His historical method was distinguished by his thorough and sensitive use of historical sources, and by his determinedly historical perspective. Maitland taught his students, and all later historians, not to investigate the history of law purely or mostly by reference to the needs of the present, but rather to consider and seek to understand the past on its own terms. His death in 1906 at Gran Canaria from tuberculosis deprived English law and letters of an outstanding representative.

He married Florence Henrietta Fisher and they had two daughters, Ermengard and Fredegond; after Maitland's death his widow married Francis Darwin, the son of Charles Darwin.

The Squire Law Library of the Faculty of Law at the University of Cambridge contains the Maitland Legal History Room. The Maitland Historical Society of Downing College, Cambridge, is named in his honour. He is commemorated in Poet's Corner, Westminster Abbey.