  This article addresses the local boundedness and H\"older continuity of weak
solutions to kinetic Fokker-Planck equations with general transport operators
and rough coefficients. These results are due to the mixing effect of diffusion
and transport. Although the equation is parabolic only in the velocity
variable, it has a hypoelliptic structure provided that the transport part
$\partial_t+b(v)\cdot\nabla_x$ is nondegenerate in some sense. We achieve the
results by revisiting the method, proposed by Golse, Imbert, Mouhot and Vasseur
in the case $b(v)= v$, that combines the elliptic De Giorgi-Nash-Moser theory
with velocity averaging lemmas.
