Retinal oximetry, which refers to the measurement of the oxygen saturation of haemoglobin in retinal blood, has emerged as a promising tool for understanding ocular and systemic diseases over the past few decades. Advances in traditional dual-wavelength measurement techniques, as well as their integration with more advanced technologies, have driven significant progress in the field. Researchers have utilised commercially available devices to explore the applications of retinal oximetry in both healthy individuals and various disease states. To provide a comprehensive overview of the current status and development trends of retinal oximetry in ophthalmology, this review analyses relevant studies on retinal oximetry, including its principles, techniques, instrumentation, and applications in healthy individuals, ocular diseases, and systemic disorders. As a biomarker, retinal oximetry provides reliable insights into the retinal and systemic microcirculation in a noninvasive, rapid, and convenient manner. It has demonstrated potential value in the measurement of standardised data and in contributing to the understanding of disease mechanisms. However, its measurement accuracy is influenced by factors such as vessel diameter, retinal pigmentation, and optical media transparency. Future advancements, including wide-field imaging technology, nonmydriatic technology, integration with blood flow measurement techniques, and artificial intelligence, are expected to further improve the accuracy and clinical application potential of retinal oximetry.