DFT calculations revealed that 1,8-diazanaphthalene di-N-oxides provide extraordinary oxygen superbases, whose gas-phase and acetonitrile basicities surpass those of classical naphthalene-based nitrogen proton sponges. Such high basicity is almost entirely a consequence of a large strain-induced destabilization in neutral forms, while only a small contribution is offered by the intramolecular [O-H···O](-) hydrogen bonding upon protonation.