Charles Henry Gordon-Lennox, 6th Duke of Richmond, 6th Duke of Lennox, and 1st Duke of Gordon KG PC (27 February 1818 – 27 September 1903), styled Lord Settrington until 1819 and Earl of March between 1819 and 1860, was a British Conservative politician.

Born at Richmond House, London, he was the son of Charles Lennox, 5th Duke of Richmond and Lennox and Lady Caroline, daughter of Field Marshal Henry Paget, 1st Marquess of Anglesey. He was educated at Westminster and Christ Church, Oxford, where he had a short career as a cricketer. He served in the Royal Horse Guards and was aide-de-camp to the Duke of Wellington.

March entered politics as member for Sussex West in 1841. He was sworn of the Privy Council in 1859. In 1860, he succeeded his father as Duke of Richmond and entered the House of Lords. He chaired the Royal Commission on Capital Punishment, which reported in 1866. He was made a Knight of the Garter in 1867, and filled various positions in government. He was also Chancellor of the University of Aberdeen from 1861 until his death at Gordon Castle in 1903.

The title Duke of Richmond is named after Richmond and its surrounding district of Richmondshire, and has been created several times in the Peerage of England for members of the royal Tudor and Stuart families. The current lineage and title was created in 1675 for Charles Lennox, the illegitimate son of King Charles II of England and a Breton noblewoman called Louise de Kérouaille.

The Dukedom was first created (as Duke of Richmond and Somerset) for Henry Fitzroy, the illegitimate son of Henry VIII (a Tudor) by Elizabeth Blount. Upon his death without children in 1536 it became extinct.

Ludovic Stuart, second Duke of Lennox (see Lennox (district)) (1574–1624), who also held other titles in the peerage of Scotland, was created Earl of Richmond in 1613 and Duke of Richmond in 1623 as a member of the Lennox line (not unlike King James himself) in the House of Stuart. These became extinct at his death in 1624, but his Scottish honours devolved on his brother Esmé, Earl of March. Esmé's son James, the fourth Duke of Lennox (1612–1655), was created Duke of Richmond in 1641, the two dukedoms again becoming united. In 1672, on the death of James' nephew Charles, 3rd Duke of Richmond and 6th Duke of Lennox, both titles again became extinct.