  We address the perturbative renormalization of massive lattice fermions. We
derive expressions-valid to all orders in perturbation theory and for all
values of the bare fermion mass-for the rest mass, the kinetic mass, and the
wave-function renormalization factor. We obtain the fermion's self energy at
the one-loop level with a mass-dependent, $O(a)$ improved action. Numerical
results for two interesting special cases, the Wilson and
Sheikholeslami-Wohlert actions, are given. The mass dependence of these results
smoothly connects the massless and infinite-mass limits, as expected. Combined
with Monte Carlo calculations our results can be employed to determine the
quark masses in common renormalization schemes.
