Word Origin and History for salon n. 1690s, "large room or apartment in a palace or great house," from French salon "reception room" (17c.), from Italian salone "large hall," from sala "hall," from a Germanic source (cf. Old English sele, Old Norse salr "hall," Old High German sal "hall, house," German Saal), from Proto-Germanic salaz, from PIE sel- (1) "human settlement" (cf. Old Church Slavonic selo "courtyard, village," Polish siolo, Russian selo "village," Lithuanian sala "village").

Sense of "reception room of a Parisian lady" is from 1810; meaning "gathering of fashionable people" first recorded 1888 (the woman who hosts one is a salonnière). Meaning "annual exhibition of contemporary paintings and sculpture in Paris" is from its originally being held in one of the salons of the Louvre. Meaning "establishment for hairdressing and beauty care" is from 1913.

Source: http://dictionary.reference.com/browse/salon