Quantum information technology has emerged as a promising paradigm for next-generation information processing, offering transformative capabilities in quantum computing, secure communication, and precision measurement. However, the practical implementation of photonic quantum technologies requires compact, scalable, and multifunctional platforms beyond conventional bulky optical systems. Metasurfaces, composed of artificially engineered subwavelength nanostructures, provide an ultrathin and versatile platform for manipulating multiple optical degrees of freedom, including amplitude, phase, polarization, and spatial modes. These unique capabilities enable new approaches toward integrated and multifunctional photonic quantum devices.In this review, we systematically summarize recent advances in metasurface-enabled quantum optics in three major areas: quantum light sources, quantum state manipulation and measurement, and emerging quantum optical applications. We first discuss how metasurfaces enhance and control quantum light sources, including single-photon emitters, entangled photon-pair sources, and high-dimensional multiphoton quantum sources, through efficient emission enhancement, directional control, and multidimensional encoding. We then review metasurface-assisted quantum state manipulation and measurement, including polarization-state analysis, quantum interference, entanglement transformation, and multidimensional quantum state control enabled by precise engineering of optical degrees of freedom. Furthermore, representative applications in quantum imaging, quantum communication, quantum computing, and quantum sensing are highlighted. Finally, we discuss the remaining challenges and future opportunities, including improving optical efficiency, reducing fabrication-induced errors and optical losses, enhancing quantum-state fidelity, and achieving large-scale integration. This review provides a comprehensive perspective on how metasurfaces are accelerating the transition of photonic quantum technologies toward compact, scalable, and highly integrated quantum platforms.