William Balfour Baikie (21 August 1824 – 30 November 1864) was a Scottish explorer, naturalist and philologist.
Baikie was born at Kirkwall, Orkney, eldest son of Captain John Baikie, R.N. He studied medicine at Edinburgh, and, on obtaining his M.D. degree, joined the Royal Navy in 1848. He early attracted the notice of Sir Roderick Murchison, through whom he was appointed surgeon and naturalist to the Niger expedition sent out in 1854 by Macgregor Laird with government support. The death of the senior officer (Consul Beecroft) occurring at Fernando Po, Baikie succeeded to the command.
Ascending the Benue about 250 miles beyond the point reached by former explorers, the little steamer Pleiad returned and reached the mouth of the Niger, after a voyage of 118 days, without the loss of a single man. The expedition had been instructed to endeavour to afford assistance to Heinrich Barth, who had in 1851 crossed the Benue in its upper course, but Baikie was unable to gain any trustworthy information concerning him. Returning to the UK, Baikie gave an account of his work in his Narrative of an Exploring Voyage up the Rivers Kwora and Binue (1856).
In March 1857, Baikie—with the rank of British consul—started on another expedition in the Pleiad. After two years exploring the Niger, the navigating vessel was wrecked passing through some of the rapids of the river, and Baikie was unable to keep his party together. The expedition survivors were not rescued from Africa for a year. The botanist, Charles Barter, who trained at Kew Gardens and was foreman of Regent's Park of the Royal Botanic Society, London from 1851–1857, caught dysentery and died at Rabba, Nigeria in 1859. He is commemorated by the genus Barteria Hook. f. in the Passifloraceae.