Nanofluidics is an interdisciplinary field of study that bridges hydrodynamics, statistical physics, chemistry, materials science, biology, and other fields to investigate the transport of fluids and ions on the nanometric scale. The progress in this field, however, has been constrained by challenges in fabricating nanofluidic devices suitable for systematic investigations. Recent advances in two-dimensional (2D) materials have revolutionized the development of nanofluids. Their ultrathin structure and photothermoelectric response make it possible to achieve the scale control, friction limitation, and regulatory response, all of which are challenging to achieve with traditional solid materials. In this review, we provide a comprehensive overview of the preparation methods and corresponding structures of three types of 2D material-based nanofluidic devices, including nanopores, nanochannels, and membranes. We highlight their applications and recent advances in exploring physical mechanisms, detecting biomolecules (DNA, protein), developing iontronics devices, improving ion/gas selectivity, and generating osmotic energy. We discuss the challenges facing 2D material-based nanofluidic devices and the prospects for future advancements in this field.