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We argue that the gas giants Jupiter and Saturn were both formed with their rotation axes nearly perpendicular to their orbital planes, and that the large cur-rent tilt of the ringed planet was acquired in a post formation event. We identify the responsible mechanism as trapping into a secular spin-orbit resonance which couples the angular momentum of Saturn’s rotation to that of Neptune’s orbit. Strong support for this model comes from i) a near match between the precession frequencies of Saturn’s pole and the orbital pole of Neptune and ii) the current directions that these poles point in space. We show, with direct numerical inte-grations, that trapping into the spin-orbit resonance and the associated growth in Saturn’s obliquity is not disrupted by other planetary perturbations. Subject headings: planets and satellites: individual (Saturn, Neptune) — Sola