An intramolecular [2 + 2] photocycloaddition is achieved in the organic solid state via self-assembly of Ag(I) ions and an endo-ditopic bipyridine. The cations aide to organize carbon-carbon double (C═C) bonds attached to the bipyridine for the cycloaddition reaction. The C═C bonds react regioselectively and quantitatively to afford a photoproduct with edge-sharing four-, five-, and six-membered rings. Our study demonstrates the first use of a metal-organic template to direct an intramolecular [2 + 2] photodimerization in the organic solid state.