The O(alpha) corrections to gamma gamma --> f (f) over bar in the standard
model are calculated for arbitrary light fermions f. The relevant analytica
l results are listed in a form that is appropriate for practical applicatio
ns, 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(+) ar
e negligible below the electroweak scale, reach the percent level at a few
hundred GeV, and grow to about -10% at 2 TeV. The weak corrections to u (u)
over bar and d (d) over bar production have a shape similar to the one for
e(-)e(+) but they are larger by factors of about 1.4 and 3, respectively.