Heterostructured photocatalysts were prepared to have nanostructured (ns) TiO₂ shells surrounding microcrystalline (mc) cores of (Ba,Sr)TiO₃. The as‐prepared heterostructures were annealed between 400°C and 600°C to improve crystallinity and core‐shell interfacial bonding. X‐ray diffraction, electron microscopy, and gas adsorption measurements demonstrated that 50 nm thick shells composed of nanocrystalline and nanoporous TiO₂ surrounded mc‐cores such that the heterostructured particles had surface areas of 50–100 m²/g. The mc‐(Ba,Sr)TiO₃/ns‐TiO₂ core‐shell photocatalysts annealed at 600°C had slightly reduced surface areas, but had the highest rates of photochemical hydrogen production from water/methanol solutions, rates much greater than those for ns‐TiO₂ or mc‐(Ba,Sr)TiO₃ alone. Such heterostructured powders represent a new strategy for the design of efficient photocatalysts and the use of nanostructured catalytic coatings.