  Supersymmetric extensions of the standard model generically contain
additional sources of CP violation. We discuss how at one loop a potentially
large CP violating coupling of the lightest Higgs, h^0, to leptons is induced
in the minimal supersymmetric standard model (MSSM). The CP violating couplings
of h^0 in extensions of the MSSM, such as the next-to-minimal supersymmetric
standard model (NMSSM) are also considered. We indicate how this CP violation
might be observed; in particular a polarization-dependent production asymmetry,
in the context of a muon collider, provides a means to access this coupling
cleanly. In the MSSM, existing limits on the electric dipole moment (EDM) of
the electron, coupled with standard universality assumptions, severly
constrains any such signal. Nevertheless, extensions of the MSSM, such as the
NMSSM, allow CP-violating signals as large as 100%.
