William Henry Hudson (4 August 1841 – 18 August 1922), known in Argentina as Guillermo Enrique Hudson, was an Anglo-Argentine author, naturalist, and ornithologist. Born in the Argentinian pampas, where he roamed free in his youth, he observed bird life and collected specimens for the Smithsonian Institution.

The Patagonian birds Knipolegus hudsoni and Asthenes hudsoni are named after him. He later wrote about life in Patagonia, drawing special admiration for his style. His most popular work, Green Mansions (1904), a romance set in the Venezuelan forest, inspired a Hollywood movie and several other works.