Speke, John Hanning (1827–1864), a British explorer of Africa. He was the discoverer of the source of the White Nile. On his first expedition, in 1854, he explored Somaliland with Richard Burton. In 1857 Speke and Burton set out to find the source of the Nile River. They discovered Lake Tanganyika in 1858, and Speke, continuing on alone, came upon Lake Victoria later that year. In 1862 he determined that Victoria was the source of the White Nile. His discovery was disputed and was not confirmed until years after his death. Information given by Speke enabled Samuel Baker to locate Lake Albert in 1864.
Before becoming an explorer, Speke served in the army in India, where he also carried on scientific research.