The reversible trans–cis photoisomerization of azobenzene and azopyridine chromophore was used to design and exploit novel photoactive materials based on polymers and liquid crystals. This paper reviews our recent studies on several systems. These include azobenzene-containing thermoplastic elastomers that can be used to prepare mechanically tunable diffraction gratings, side-chain azopyridine polymers for combined self-assembly and photoactivity, azobenzene polymer-stabilized ferroelectric liquid crystals whose bulk alignment can be achieved by light with no need for surface orientation layers, and, finally, self-assembled photoactive liquid-crystal gels that can display light-induced reorganization leading to the formation of electrically switchable diffraction gratings.