Recently, transition metal-based carbides and nitrides, recognized as MXenes, have gained recognition as next-generation two-dimensional (2D) systems. They have garnered substantial consideration due to their potential in various applications, especially in photocatalytic water splitting. MXene-based composite materials are considered efficient photocatalysts because of their unique interfacial interactions, which promote effective charge separation upon photoirradiation. This makes them promising candidates as efficient and innovative photocatalysts in various applications, including water splitting. This chapter provides a comprehensive overview of general photocatalysis and MXenes, along with their fundamental mechanisms. The criteria for an ideal photocatalyst to enhance photocatalytic performance are discussed. This is followed by a detailed examination of the structure and synthesis of MXenes and how their features can be tailored for efficient photocatalytic H2 production. We also summarize various MXene-based systems used in photocatalysis and the computational modeling of MXenes, particularly for hydrogen (H2) production via water splitting. In conclusion, we discuss the pros and cons of MXene-based systems and offer insights into the cutting-edge research and computational modeling of materials incorporating MXenes for photocatalytic applications.