Thomas Alexander Barns FZS FES (4 June 1881 – 4 March 1930), known in his private life as Alexander Barns, was an English businessman, explorer, big game hunter, author, artist, naturalist and lecturer connected with the opening up of Central Africa by Europeans in the early 20th century. The amateur entomologist James John Joicey commissioned Barns to collect specimens of lepidoptera in Africa on his behalf.