  The $O(\alpha)$ corrections to $\gamma\gamma --> f \bar f$ in the Standard
Model are calculated for arbitrary, light fermions $f$. The relevant analytical
results are listed in a form that is appropriate for practical applications,
and numerical results for integrated cross sections are discussed. The
corresponding QED corrections are generally of the order of some per mille for
arbitrary energies. The weak corrections to $\gamma\gamma --> e^-e^+$ are
negligible below the electroweak scale, reach the per-cent level at a few
hundred GeV and grow to about -10% at 2TeV. The weak corrections to $u \bar u$
and $d \bar d$ production have a shape similar to the one for $e^-e^+$, but
they are larger by factors $\sim 1.4$ and $\sim 3$, respectively.
