  Two--photon decays of Higgs bosons are important channels for the search of
these particles in the intermediate mass range at the $pp$ colliders LHC and
SSC. Dynamical aspects of the Higgs coupling to two photons can also be studied
by means of the $\gamma \gamma$ fusion of Higgs particles at high--energy
e$^+$e$^-$ linear colliders. Extending earlier analyses which had been
restricted to the Standard Model, we present in this note the QCD radiative
corrections to the $\gamma \gamma$ decay widths of scalar and pseudoscalar
Higgs particles in multi--doublet extensions of the Higgs sector, as realized
for instance in supersymmetric theories.
