Francis William Ogilvy-Grant, 6th Earl of Seafield (6 March 1778 – 30 July 1853) was a Scottish nobleman, a Member of Parliament and is listed as the 25th Chief of The Clan Grant.
The family of Grant of Grant, on succeeding in 1811 to the Earldom of Seafield, first adopted the surname of Grant-Ogilvie, otherwise Grant-Ogilvy. This order was later reversed, so that Lord Cassillis' history, 'The Rulers of Strathspey' (1911) names the 5th, 6th, 7th and 8th Earls as Grant-Ogilvie but all their successors from Sir James, 9th Earl, as Ogilvie-Grant. Sir William Fraser's 'The Chiefs of Grant' (1884) preferred the style of Grant of Grant and Lord Ogilvie of Deskford and Cullen for both the 5th and 6th Earls; his article on the 7th Earl is named Sir John Charles Grant Ogilvie but the accompanying portrait is named Sir John Charles Ogilvie Grant, Baronet, Seventh Earl of Seafield etc. For the sake of consistency, historical works and articles (including this series) often retrospectively reassign the spelling and order of these family names.
In 2017 The family name of the Earl of Seafield is Ogilvie-Grant according to the Seafield Estates.
Born 6 March 1778, the Hon. Francis William Grant was the fourth son of Sir James Grant, 8th Baronet, and Jane Duff. In 1811 he married Mary Anne Dunn, daughter of John Dunn, and they had five children. After his first wife's death (1840), he married Louisa Emma, daughter of Robert George Maunsell, in 1843. Owing to the mental incapacity of his brother Sir Lewis Alexander Grant (and the earlier deaths of two older brothers) from 1811 he acted as Curator of the Grant Estates and those of the Seafield Earldom until he succeeded as Earl of Seafield in his own right in 1840. Lord Seafield died in July 1853, aged 75, and was buried at the mausoleum at Duthil Old Parish Church and Churchyard, just outside the village of Duthil, Inverness-shire. He was succeeded in his titles by his third son from his first marriage, John Charles Ogilvy-Grant.