Quick answer
Thelma is a girl name.
Meaning and history
Meaning unknown. It was a rare name when British author Marie Corelli used it 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 θέλημα (thelema) meaning "will", though this seems unlikely.
Notes and context
Usage: english