Baron Redesdale, of Redesdale in the County of Northumberland, is a title that has been created twice in the Peerage of the United Kingdom. It was firstly created in 1802 for the lawyer and politician Sir John Mitford (later Freeman-Mitford).^[1] The title was created anew in 1902 for the former's cousin Algernon Bertram Mitford.

The Mitford family is an aristocratic English family, with origins in medieval Northumberland where they held Mitford Castle. Sir John Mitford was Speaker of the House of Commons between 1801 and 1802 and Lord Chancellor of Ireland between 1802 and 1806. His only son, the second Baron, served as Chairman of Committees in the House of Lords from 1851 to 1886. In 1877, he was created Earl of Redesdale, in the County of Northumberland, in the Peerage of the United Kingdom.^[2] Lord Redesdale never married, and on his death in 1886 both titles became extinct. The Earl bequeathed his substantial estates to his first cousin twice removed, the diplomat, politician and writer Sir Algernon Bertram Mitford, the great-grandson of historian William Mitford, who was the elder brother of the first Baron Redesdale.

The Redesdale title was revived when Algernon Freeman-Mitford was raised to the peerage as Baron Redesdale, of Redesdale in the County of Northumberland, on 15 July 1902.^[3] He was succeeded by his second but eldest surviving son, David Freeman-Mitford, 2nd Baron Redesdale, who is chiefly remembered as the father of the famous Mitford sisters. He was also a member of the Right Club, founded by Archibald Maule Ramsay. His only son, the Hon. Thomas Freeman-Mitford, was killed in action in Burma in 1945.

Lord Redesdale was therefore succeeded by his younger brother, the third Baron. He was High Sheriff of Oxfordshire in 1935. He died childless in 1962 when the title passed to his younger brother, the fourth Baron. He died in the following year, also childless, and was succeeded by his nephew, the fifth Baron. He was the son of the Hon. Ernest Rupert Bertram Ogilvy Freeman-Mitford, fifth son of the first Baron.

As of 2020^[update], the title is held by the fifth Baron's son, the sixth Baron, who succeeded in 1991. He is a Liberal Democrat member of the House of Lords, who in 2000 was created a life peer as Baron Mitford, of Redesdale in the County of Northumberland,^[4] to enable him to return to the House after the majority of hereditary peers lost their seats under the House of Lords Act 1999.

• John Freeman-Mitford, 1st Baron Redesdale (1748–1830)
• John Thomas Freeman-Mitford, 2nd Baron Redesdale (1805–1886; created Earl of Redesdale in 1877)

• Algernon Bertram Freeman-Mitford, 1st Baron Redesdale (1837–1916)
• David Bertram Ogilvy Freeman-Mitford, 2nd Baron Redesdale (1878–1958)
• Bertram Thomas Carlyle Ogilvy Freeman-Mitford, 3rd Baron Redesdale (1880–1962)
• John Power Bertram Ogilvy Freeman-Mitford, 4th Baron Redesdale (1885–1963)
• Clement Napier Bertram Freeman-Mitford, 5th Baron Redesdale (1932–1991)
• Rupert Bertram Mitford, 6th Baron Redesdale (b. 1967)

The heir apparent is the present holder's eldest son, the Hon. Bertram David Mitford (b. 2000).

• William Mitford
• Mitford sisters