Due to the rapidly increasing demand for energy and environmental sustainability, stable and economical hydrogen production has received increasing attention in the past decades. In this regard, hydrogen production through photo- or electrocatalytic water splitting has con-tinued to gain ever-growing interest. However, the existing catalysts are still unable to fulfill the demands of high-efficiency, low-cost, and sustainable hydrogen production. Layered metal trichalcogenidophosphate (MPQ3) is a newly developed two-dimensional material with tunable composition and electronic structure. Recently, MPQ3 has been considered a promising candidate for clean energy generation and related water splitting applications. In this minireview, we firstly introduce the structure and methods for the synthesis of MPQ3 materials. In the following sections, recent developments of MPQ3 materials for photo- and electrocatalytic water splitting are briefly summarized. The roles of MPQ3 materials in different reaction systems are also discussed. Finally, the challenges related to and prospects of MPQ3 materials are presented on the basis of the current developments.