A new class of supramolecular metallacycles capable of undergoing photochemical reactions and in situ release of cyclobutanes in solution is described. The molecular metallacycles were generated through coordination‐driven self‐assembly of dinuclear metal‐carbene complexes as organometallic clips with olefin‐functionalized bridging ligands. Photolysis of these molecular metallacycles in situ led to structural interconversion and release of the formed cyclobutane products with quantitative conversion. Further modifications of the obtained cyclobutanes provided a series of new species containing the cyclobutane skeleton. Catch and release: Photolysis of the pictured molecular metallacycles in situ leads to quantitative cycloaddition and release of the stereoselectively formed cyclobutane products. The pendant groups on the products include pyridyl, imidazole, benzimidazoles, and carboxylic derivatives.