Composite target rf magnetron sputtering has previously been successfully employed to make superconducting films of YBa2Cu3O7−xin‐situat substrate temperature Ts<700 °C. We report the successful growth of superconducting films of Bi2Sr2CaCu2Oxon single crystal MgO substrates by a low‐temperature process using dc magnetron sputtering from a Bi‐enriched composite target. Using a substrate temperature Ts≊645 °C, metallic films with a superconducting onset of 90–100 K and an extrapolated Tc0=56 K have been obtained. X‐ray diffraction shows the films to be c‐axis oriented. Electron microscopy reveals that the films are not significantly smoother nonsuperconducting phases had occurred. The exact mechanism by which crystallization and superconductivity occurs at such low temperatures is not yet known, but it can be speculated that the surface atoms are less constrained and thus have a smaller energy barrier to overcome in forming a crystal structure.