  Building on earlier work on electroweak corrections to W-pair production, the
first calculation of the full electroweak one-loop corrections to on-shell ZZ,
W$^{\pm}$Z and $\gamma\gamma$ production at hadron colliders is presented,
explicitly taking into account the full vector-boson mass dependence. As a
consequence, our results are valid in the whole energy range probed by LHC
experiments. Until now, the electroweak corrections have only been known in
dedicated high-energy approximations limited to a specific kinematic regime, in
particular requiring high boson transverse momenta. Therefore, our results
comprise an important and so far missing ingredient to improve on the theory
predictions for these fundamental Standard-Model benchmark processes also at
intermediate energies and small scattering angles, where actually the bulk of
events is located. In case of Z-pair production we have also included the
leptonic decays and the associated weak corrections in our analysis. For this
particular channel, corrections of about -4% are observed even close to the
production threshold. For hard scattering processes with momentum transfers of
several hundred GeV one finds large negative corrections which may amount to
several tens of percent and lead to significant distortions of
transverse-momentum and rapidity distributions.
