Optical coherence tomography (OCT) is a noninvasive or minimally invasive imaging technique with high-resolution and real-time visualization capabilities, providing depth information of tissues. It is widely applied in biomedical imaging and clinical diagnostics. Fiber-optic endoscopy based on OCT is an imaging technique employing fiber transmission and fiber endoscopic imaging, which combines the benefits of conventional OCT with features such as compact size, lightweight design, corrosion resistance, electrical insulation, and resistance to electromagnetic interference. This technique excels in high-resolution detection and early diagnosis of tissue abnormalities within narrow luminal structures, overcoming the limitations of existing imaging technologies. Advancements in laser, detector, and optical fiber device fabrication technologies have led to considerable progresses in the design and fabrication of OCT systems and fiber-optic probes, expanding the applications of fiber OCT. Notably, the evolution of fiber OCT systems from time-domain to frequency-domain OCT has resulted in remarkable improvements in imaging speed and resolution. The development of fiber-optic endoscopic OCT imaging probes has traversed three stages: the fiber-prism probe, all-fiber probe, and composite fiber probe. This progression is marked by advancements toward multifunctional integration, miniaturization, and overall integration. The clinical applications of fiber-optic endoscopic OCT have extended beyond the respiratory and digestive systems to encompass the cardiovascular system. This article offers a comprehensive overview of research progresses in fiber-optic endoscopy based on OCT, examining three key perspectives: the evolution of fiber OCT systems, design and fabrication of fiber-based imaging probes, and their recent applications in endoscopic imaging. Ultimately, in conjunction with state-of-the-art technologies, a prospective outlook is presented on the future development of fiber-optic endoscopic OCT techniques.