The interpretation of complex eigenvalues of linear transformations defined on a real geometric algebra presents problems in that their geometric significance is dependent upon the kind of linear transformation involved, as well as the algebraic lack of universal commutivity of bivectors. The present work shows how the machinery of geometric algebra can be adapted to the study of complex linear operators defined on a unitary space. Whereas the well-defined geometric significance of real geometric algebra is not lost, the primary concern (...) here is the study of the algebraic properties of complex eigenvalues and eigenvectors of these operators. (shrink)