Thelma Holmes was a Gryffindor student at Hogwarts School of Witchcraft and Wizardry in the 1990s. As a lover of wizard's chess, she collected chess pieces, and traded her spare ones with other students for other objects (Gobstones, Chocolate Frog Cards and Butterbeer). She could usually be found in the Entrance Courtyard during the 1996–1997 school year.
The Meaning of the name "Thelma" is unknown. It was a rare name when it was used by British author Marie Corelli for the Norwegian heroine of her novel 'Thelma' (1887). The name became popular around the end of the 19th century after the novel was published. It is sometimes claimed to derive from Greek θελημα (thelema) meaning "will", though this seems unlikely.