Emerging hierarchical MoS₂/pillared-montmorillonite (MoS₂/PMMT) hybrid nanosheets were successfully prepared through facile in-situ hydrothermal synthesis of MoS₂ within the interlayer of cetyltrimethylammonium bromide PMMT, and their catalytic performance was evaluated by the reduction reaction of 4-nitrophenol (4-NP) using NaBH₄ as a reductant. Microstructure and morphology characterization indicated that MoS₂/PMMT exhibited hybrid-stacked layered structures with an interlayer spacing of 1.29 nm, and the MoS₂ nanosheets were intercalated within the montmorillonite (MMT) layers, with most of the edges exposed to the outside. The catalytic activity and stability of MoS₂/PMMT were both enhanced by the MMT. With the MoS₂/PMMT as the catalyst, the apparent reaction rate constant of the 4-NP reduction was 0.723 min^-1 and was maintained at ~0.679 min^-1 after five reaction cycles. The structural evolution of MoS₂/PMMT and the possible catalysis mechanism for the reduction reaction of 4-NP were investigated. The as-prepared MoS₂/PMMT hybrid nanosheets are promising candidates for catalytic application in the water-treatment and biomedical fields. The strategy developed in this study can provide insights for designing hybrid nanosheets with diverse heterogeneous two-dimensional (2D) nanomaterials.