<p>Self-luminescence imaging, which eliminates the need for external excitation, offers a compelling advantage in bioimaging by providing superior signal-to-background ratios for visualizing deep-seated biological structures and events. The performance of this advanced technique hinges on the properties of its self-luminous probes. Among various options, small-molecule organic probes (SOMSPs) have emerged as a promising class due to their exceptional molecular programmability, high sensitivity, and tunable optical characteristics. Recent breakthroughs in novel SOMSP design, their synergistic integration with advanced nanomaterials, and innovative combinations with therapeutic modalities have further amplified their sensitivity, selectivity, and versatility in diverse biomedical applications. This provides a comprehensive synthesis of the current state-of-the-art in organic small-molecule probes for self-luminescence techniques, with a specific focus on chemiluminescence, bioluminescence, and afterglow luminescence. We delineate key interdisciplinary strategies for their design and optimization, highlighting their broad applications in cancer diagnosis and targeted therapy, as well as real-time neuronal activity monitoring. Finally, we discuss the persistent challenges and offer a forward-looking perspective on future directions to accelerate the clinical translation of SOMSP-based self-luminescence imaging, bridging fundamental materials science with advanced biomedical engineering.</p>