<p>Room-temperature magnetic semiconductors are crucial for next-generation spintronics, yet remain hindered by low Curie temperatures and volatile control mechanisms. Using density functional theory, we report Cr₂NiSe₄, a bipolar magnetic semiconductor (BMS) formed by Ni intercalation in bilayer CrSe₂, with a Curie temperature of 495 K and a 0.40 eV band gap. We demonstrate nonvolatile control over carrier spin polarization in Al₂Se₃ heterostructures via ferroelectric switching: reversing the polarization of monolayer Al₂Se₃ induces a BMS-to-half-metal transition, whereas bilayer Al₂Se₃ enables half-metallic states with fully opposite spin polarization. This nonvolatile mechanism obviates the need for a continuous electric field and lowers energy consumption through interfacial charge transfer driven by ferroelectric band alignment. We propose a multiferroic memory device where ferroelectric polarization controls writing and spin-dependent conductance enables reading, enabling low-power, room-temperature operation. Our work establishes a feasible pathway for developing electrically tunable spintronics beyond the limits of Moore’s Law.</p>