Osborne Markham (27 May 1769 – 22 October 1827) was a British politician, MP for Calne 1806–1807. Markham was the sixth son of William Markham, Archbishop of York. He was educated at Westminster School and Christ Church, Oxford, matriculating in 1787 aged 18, graduating B.A. 1791, M.A. 1794. He was called to the bar at Lincoln's Inn in 1794. Markham's father, Archbishop Markham, appointed him Chancellor of the Diocese of York soon after he qualified, in 1795. Although he subsequently gave up the legal profession, he retained the chancellorship, as a sinecure, until 1818.