  Lorentz-violating theories of gravity typically contain constrained vector
fields. We show that the lowest-order coupling of such vectors to
$\mathrm{U}(1)$-symmetric scalars can naturally give rise to baryogenesis in a
manner akin to the Affleck-Dine mechanism. We calculate the cosmology of this
new mechanism, demonstrating that a net $B-L$ can be generated in the early
Universe, and that the resulting baryon-to-photon ratio matches that which is
presently observed. We discuss constraints on the model using solar system and
astrophysical tests of Lorentz violation in the gravity sector. Generic
Lorentz-violating theories can give rise to the observed matter-antimatter
asymmetry without violating any current bounds.
