  Four topics in theory of CP violation are reviewed. (a) CP violation in $B$
decays: We describe a new clean way of constraining the angle $\gamma$ of the
unitarity triangle and how new CP violation in decay amplitudes can signal new
physics. (b) CP violation in $K$ decays: We explain the special features of the
decay $K_L\ra\pi^0\nu\bar\nu$ both as a measurement of Standard Model CP
violating parameters and as a probe of new physics. (c) CP violation in $D$
decays: We describe the consequences of CP violation from new physics in
$D-\bar D$ mixing. (d) CP violation in Supersymmetry: We explain how a
combination of measurements of CP violating processes will give insight into
the flavor and CP structure of supersymmetry.
