The quest for mechanoluminescence (ML) in zinc sulfide (ZnS) spans more than a century, initially sparked by observations of natural minerals. There has been a resurgence in research into ML materials in recent decades, driven by advances in optoelectronic technologies and a deeper understanding of their luminescent properties under mechanical stress. ZnS, in particular, has garnered attention owing to its remarkable ability to sustain luminescence after more than 100,000 mechanical stimulations, positioning it as a standout candidate for optoelectronic applications. In contrast to conventional photoluminescent and electroluminescent light sources, ZnS composite elastomers have emerged as flexible, stretchable self-powered light sources with considerable practical implications. This review introduces the development history, ML mechanisms, prototype ML devices, ZnS-based ML material preparation methods, and their diverse applications spanning environmental mechanical-to-optical energy conversion, E-signatures, anti-counterfeiting, wearable information sensing devices, advanced battery-free displays, biomedical imaging, and optical fiber sensors for human–computer interactions, among others. By integrating insights from ML-optics, mechanics, and flexible optoelectronics, and by summarizing pertinent perspectives on current scientific challenges, application technology hurdles, and potential solutions for emerging scientific frontiers, this review aims to furnish fundamental guidance and conceptual frameworks for the design, advancement, and cutting-edge application of novel mechanoluminescent materials.