Thomas Gwyn Elger was a 19th century lunar scholar and director of the Lunar Section of the British Astronomical Association. Elger was trained as a civil engineer. He is best known as a careful and indefatigable selenographer. His best-known work was The Moon: A full Description and Map of its Principal Physical Features. Published in 1895, its maps are still highly regarded by lunar observers due to their uncluttered nature. The lunar crater Elger was named for him.