1950s: from French discothèque, originally 'record library', on the pattern of bibliothèque 'library'.
English writers commented on the French discothèque in the 1950s. Originally it was a record library (on the model of bibliothèque ‘library’), then a club where recorded music was played for dancing. By the 1960s the English-speaking world had opened its own discotheques, and the USA very quickly shortened the word to disco. See also jukebox