Abstract: Litchi is the main characteristic fruits of the subtropical region. As the world's leading producer of litchi, China ranks first globally in both cultivation area and yield. The byproducts generated during litchi processing, e.g., shells and seeds, are rich in phenolic compounds like A-type proanthocyanidins, and contain various isomers. However, there is a lack of systematic reviews on the recent research progress regarding litchi proanthocyanidins. Therefore, this paper aims to provide a comprehensive review of the structure, extraction methods, and bioactive functions of litchi proanthocyanidins. Currently, research on the chemical structure of litchi proanthocyanidins mainly focuses on elucidating their structural units, degree of polymerization, molecular weight distribution and major chemical composition. The extraction methods primarily involve multiple techniques, including traditional solvent, microwave-assisted, deep eutectic solvent, ultrasound-assisted, ultrasound-microwave synergistic, and ultra-high pressure-assisted extractions. In terms of functional activities, the biological activities of lychee proanthocyanidins, such as antioxidant, hepatoprotective, hypoglycemic, anti-inflammatory, and improvement of Alzheimer's disease, are summarized in detail. Finally, this paper provides an outlook on future research directions and development trends of litchi proanthocyanidins, aiming to offer theoretical guidance and references for their applications in the food industry.