Accurate gas-phase and solution-phase valence bond calculations reveal that protonation of the hydroxyl group of aliphatic alcohols transforms the C − O bond from a principally covalent bond to a complete charge-shift bond with principally “ no-bond ” character. All bonding in this charge-shift bond is due to resonance between covalent and ionic structures, which is a di ff erent bonding mechanism from that of traditional covalent bonds. Until now, charge-shift bonds have been previously identi fi ed in inorganic compounds or in exotic organic compounds. This work showcases that charge-shift bonds can occur in common organic species.