James Hornell (1865 – February 1949) was an English zoologist and seafaring ethnographer. He was a cousin of Edward Atkinson Hornel, a Scottish painter.
As a zoologist Hornell published a number of papers on marine organisms working most notably with his father in law Joseph Sinel in Jersey, and in 1900 traveled to Ceylon (now Sri Lanka) to report on the pearl fisheries. Staying there for six years, Hornell published a number of papers on the pearling industry. While there he was elected a Fellow of the Linnean Society for his work on marine worms. After working for several more years in India, organizing the fisheries of Madras, he retired, and thus began his next career as an ethnographer of seafarming and maritime life. He traveled extensively around the Indian Ocean world and east Asia, making records of indigenous watercraft, sailing on Junks and Sampans, and as a member of an expedition to the south seas made many records of the watercraft of Polynesia. Further travels brought encounters with watercraft of northern India, the Mediterranean, the Nile, Uganda, Madagascar, Iraq, and northern Europe.
Hornell in the 1930s became the principal authority on traditional, indigenous watercraft particular logboats, skin boats, canoes of all types, floats and even small ships. His work is distinguished by careful observation and measurement and supported by drawings and photographs of seafaring life all but vanished over the second half of the twentieth century.
James Hornell also collected string games. He collected string figures from Africa, Asia and Pacifics Islands.