James Gairdner was a British historian. He specialized in 15th-century and early Tudor history, and among other tasks edited the Letters and Papers of the Reign of Henry VIII series.
Son of John Gairdner, M.D. and brother of Sir William Tennant Gairdner, he was born and educated in Edinburgh. He entered the Public Record Office in London in 1846, becoming assistant keeper of the public records (1859–1893). Gairdner's contributions to English history related chiefly to the reigns of Richard III, Henry VII and Henry VIII. For the Rolls Series he edited Letters and Papers illustrative of the Reigns of Richard III and Henry VII (London, 1861–1863), and Memorials of Henry VII (London, 1858). He succeeded J. S. Brewer in editing the Letters and Papers, foreign and domestic, of the reign of Henry VIII (London, 1862–1905).
He brought out the then best edition of the Paston Letters (London, 1872–1875, and again 1896); for the Camden Society he edited the Historical collections of a Citizen of London (London, 1876), and Three 15th-century Chronicles (London, 1880). His other works included well-known monographs on Richard III (London, 1878), and on Henry VII (London, 1889, and subsequently); The Houses of Lancaster and York (London, 1874, and other editions); The English Church in the 16th century (London, 1902); Lollardy and the Reformation in England (1908); and contributions to the Encyclopædia Britannica, the Dictionary of National Biography, the Cambridge Modern History, and the English Historical Review. Gairdner received the honorary degree of LL.D. from the University of Edinburgh in 1897, and was made a Commander of the Order of the Bath in 1900.