Superconductivity serves as a unique solid-state platform for electron interference at a devicerelevant lengthscale, which is essential for quantum information and sensing technologies. As opposed to semiconducting transistors that are operated by voltage biasing at the nanometer scale, superconductive quantum devices cannot sustain voltage and are operated with magnetic fields, which impose a large device footprint, hindering miniaturization and scalability. Here we introduce a system of superconducting materials and devices that have a common interface with a ferroelectric layer. An amorphous superconductor was chosen for reducing substrate-induced misfit strain and for allowing low-temperature growth. The common quantum pseudowavefunction of the superconducting electrons was controlled by the non-volatile switchable polarization of the ferroelectric by means of voltage biasing. A controllable change of 21% in the critical temperature was demonstrated for a continuous film geometry. Moreover, a controllable change of 54% in the switching current of a superconducting quantum interference device (SQUID) was demonstrated. The ability to voltage bias superconducting devices together with the non-volatile nature of this system paves the way to quantum-based memory devices.