The possibility of spontaneous breaking of CP symmetry by the expectationvalues of orbifold moduli is investigated with particular reference to $CP$violating phases in soft supersymmetry breaking terms. The effect of differentmechanisms for stabilizing the dilaton and the form of the non-perturbativesuperpotential on the existence and size of these phases is studied. Modelswith modular symmetries which are subgroups of $PSL(2,Z)$, as well as thesingle overall modulus $T$ case with the full $PSL(2,Z)$ modular symmetry, arediscussed. Non-perturbative superpotentials involving the absolute modularinvariant $j(T)$, such as may arise from F-theory compactifications, areconsidered.