From Longman Dictionary of Contemporary Englishstage nameˈstage ˌname noun [countable] APTNAME OF A PERSONa name used by an actor instead of his or her real name
Examples from the Corpus
stage name• Known only be a stage name, he is pure role.• Alice entered the competition in London under a stage name Lavender Lee.• Born Alice Nilsson, Babs adopted her stage name as a teenage star in radio, records and film.• In Ross v Hopkinson, an actress sued the publisher of a novel in which a character bore her stage name.• Louis Maddox: but his stage name was Orso.• She began acting in her childhood under the stage name Marjorie Moore.• His companion chuckled at the jest, but Gravelet, whose stage name was Blondin, was deadly serious. 