James Augustus Grant, CB, CSI, FRS, FRGS was a Scottish explorer of eastern equatorial Africa.
Grant was born at Nairn in the Scottish Highlands, where his father was the parish minister, and educated at Nairn Academy, Aberdeen Grammar School and Marischal College, Aberdeen. In 1846 he joined the Indian army. He saw active service in the Sikh War, served throughout the Indian Mutiny of 1857, and was wounded in the operations for the relief of Lucknow.
He returned to England in 1858, and in 1860 joined John Hanning Speke in the memorable expedition which solved the problem of the Nile sources. The expedition left Zanzibar in October 1860 and reached Gondokoro, where the travellers were again in touch with what they regarded civilization, in February 1863. Speke was the leader, but Grant carried out several investigations independently and made valuable botanical collections. He acted throughout in absolute loyalty to his comrade.
In 1864 he published, as supplementary to Speke's account of their journey, A Walk across Africa, in which he dealt particularly with "the ordinary life and pursuits, the habits and feelings of the natives" and the economic value of the countries traversed. In 1864 he was awarded the patron's medal of the Royal Geographical Society, and in 1866 given the Companionship of the Bath in recognition of his services in the expedition.