AbstractCorrelated oxides and related heterostructures are intriguing for developing future multifunctional devices by exploiting their exotic properties, but their integration with other materials, especially on Si‐based platforms, is challenging. Here, van der Waals heterostructures of La_0.7Sr_0.3MnO₃ (LSMO) , a correlated manganite perovskite, and MoS₂ are demonstrated on Si substrates with multiple functions. To overcome the problems due to the incompatible growth process, technologies involving freestanding LSMO membranes and van der Waals force‐mediated transfer are used to fabricate the LSMO‐MoS₂ heterostructures. The LSMO‐MoS₂ heterostructures exhibit a gate‐tunable rectifying behavior, based on which metal‐semiconductor field‐effect transistors (MESFETs) with on‐off ratios of over 10⁴ can be achieved. The LSMO‐MoS₂ heterostructures can function as photodiodes displaying considerable open‐circuit voltages and photocurrents. In addition, the colossal magnetoresistance of LSMO endows the LSMO‐MoS₂ heterostructures with an electrically tunable magnetoresponse at room temperature. This work not only proves the applicability of the LSMO‐MoS₂ heterostructure devices on Si‐based platform but also demonstrates a paradigm to create multifunctional heterostructures from materials with disparate properties.