LAUSR

Despite extensive studies on magnetic proximity effects, the fundamental excitonic properties of the 2D semiconductor‐magnet heterostructures remain elusive. Here, the presence of localized excitons in MoSe2/CrSBr heterostructures is unveiled, represented by a new photoluminescence emission feature, X*. Our findings reveal that X* originates from excitons confined by intrinsic defects in the CrSBr layer. Additionally, the degrees of valley polarization of the X* and trion peaks exhibit opposite polarities under a magnetic field and closely correlate with the magnetic order of CrSBr. This is attributed to spin‐dependent charge transfer across the heterointerface, supported by density functional theory calculations which reveal a type‐II band alignment. Furthermore, the strong in‐plane anisotropy of CrSBr induces unique polarization‐dependent responses in MoSe2 emissions. This study highlights the crucial role of defects in shaping excitonic properties and offers valuable insights into spectrally resolved proximity effects in semiconductor‐magnet van der Waals heterostructures.