Straightener may refer to:
Straightener (band), Japanese alternative rock band A straightening iron, a kind of hair iron Any substance used in hair straightening A shaft straightener, a device used in making an arrow or spear Flow straightener, a key element of a wind tunnel Straightener (metalworking), a device used in metalworking to straighten material before it is fed to a stamping press "Wheels of Confusion/The Straightener", a song from Black Sabbath Vol. 4