  As a first step to a detailed study of orientifolds of Gepner models
associated with Calabi-Yau manifolds, we construct crosscap states associated
with anti-holomorphic involutions (with fixed points) of Calabi-Yau manifolds.
We argue that these orientifolds are dual to M-theory compactifications on
(singular) seven-manifolds with $G_2$ holonomy. Using the spacetime picture as
well as the M-theory dual, we discuss aspects of the orientifold that should be
obtained in the Gepner model. This is illustrated for the case of the quintic.
