Block copolymers are capable of forming different ordered phases at nanoscopic length scales. When block copolymers are placed with hard templates of different shapes and sizes, confining environments strongly constrain the possible morphologies that can be formed by the block copolymers. The interplay between the symmetry, length scale, and polymer–wall interactions leads to a plethora of novel and complex morphologies that could not be obtained in bulk block copolymer systems, thus providing opportunities to engineer novel nanostructures. Some principles of the formation of confined block copolymer morphologies are obtained from a large number of experimental and theoretical studies.