Two-dimensional (2D) multiferroics that simultaneously host ferroelectricity and magnetism represent a frontier platform for next-generation electronics and spintronics. Here we demonstrate that Cr₂S₃ thin film serves as a rare intrinsic room-temperature sliding multiferroic with coexisting ferroelectric, ferromagnetic, and ferrovalley orders. Crucially, interlayer sliding drives reversible ferroelectric polarization switching, resulting in a stabilized ferroelectricity with a critical temperature T_FE ~ 420 K. Furthermore, the system exhibits robust perpendicular magnetic anisotropy with intralayer and interlayer ferromagnetic coupling (T_FM ~ 300 K), sharply contrasting with the prevalent interlayer A-type antiferromagnetism in conventional sliding ferroelectrics. Remarkably, an electric field is able to achieve linear magnetoelectric coupling in Cr₂S₃ to realize electronic control of magnetism. Fundamental symmetry breaking further generates giant spontaneous valley polarization, while the antisymmetric Berry curvature mediates electrically programmable anomalous valley Hall effect. This functional integration establishes a multipath quantum control where interlayer sliding, spin orientation, and valley pseudospin are strongly coupled. This work opens routes to room-temperature atomically-scaled multistate devices, including nonvolatile memories, magnetoelectric sensors, and valleytronic logic devices.