  We show that spontaneous baryogenesis occurs automatically in relaxion models
if the reheating temperature is larger than the weak scale, provided the
Standard Model fields are charged under the U(1) of which the relaxion is a
pseudo-Nambu-Goldstone boson. During the slow roll, the relaxion breaks CPT,
biasing the thermal equilibrium in favor of baryons, with sphalerons providing
the necessary baryon number violation. We calculate the resulting baryon
asymmetry, explore the possible constraints on this scheme and show that there
is a swath of parameter space in which the current observations are matched.
Successful baryogenesis can be achieved for a range of relaxion masses between
$10^{-10}$ and $10^{-5}$ eV. The mechanism operates precisely in the region of
parameter space where recent work has shown relaxion oscillations to be a dark
matter candidate.
