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.

In 1868, at the age of thirteen, Eva Cecilia had been awarded the Royal Humane Society's Silver Medal for saving her ten-year-old sister Blanche Rosa from drowning in a pool of the River Erme at Ivy Bridge, Devon.

From 1900 to 1903 he was agent for the Tanganyika Concessions in Northern Rhodesia, where he also worked in ranching and organised expeditions to German and Portuguese East Africa, shot elephants, traded ivory, and collected zoological specimens for museums, such as a large African elephant for the South Kensington Museum.

[6] One of these trips lasted a year, when travelling with his wife Barns collected many specimens of Lepidoptera for Joicey's Hill Museum at Witley.