c.1300, "temperament, character, disposition," from Old French qualite "quality, nature, characteristic" (12c., Modern French qualité), from Latin qualitatem (nominative qualitas) "a quality, property; nature, state, condition" (said [Tucker, etc.] to have been coined by Cicero to translate Greek poiotes), from qualis "what kind of a," from PIE pronomial base *kwo- (see who).
Meaning "degree of goodness" is late 14c. Meaning "social rank, position" is c.1400. Noun phrase quality time first recorded 1977. Quality of life is from 1943. Quality control first attested 1935.