Photo-responsive species are capable of absorbing light to achieve versatile functionalities that make them of interest in a wide range of applications, including photovoltaics, selective ion transport, sensors, and lasers. For device integration, it is generally beneficial to incorporate these photo-responsive species within robust host matrices such as nanostructured inorganic-organic nanostructured composite materials. Such nanocomposites have high internal surface areas (500--1000 m2/g), large pore or channel volumes (> 1 cm3/g), adjustable compositions, high degrees of periodic ordering with uniform and controllable channel dimensions (3--12 nm), and high thermal, chemical, and mechanical stabilities. For example, in hybrid photovoltaic materials, molecular contact between a photo-responsive, electron-donating conjugated polymer and an electron-accepting titania matrix can be facilitated by co-assembling them into a nanostructured composite. Using solid-state NMR, in combination with other techniques, it has been shown that interactions of the structure-directing surfactant species with the titania matrix, along with chemical structure of the photo-responsive species, strongly influence both the interfacial interactions between the photo-responsive species and the titania network and the device power conversion efficiencies. Similar silica nanostructured composites were also used to incorporate a photo-responsive membrane protein, proteorhodopsin, at high concentrations (up to 55 wt%) for applications in selective photo-induced ion transport; furthermore it is shown that this protein remains active and has improved thermal stability in the nanostructured composite. Finally, novel nanostructured composites with high degrees of macroscopic orientational ordering have been synthesized with a variety of photo-responsive species incorporated, and it has been demonstrated that such materials have improved transport properties in photovoltaic devices.