Grapes are one of the most widely cultivated fruits and have been used for winemaking since the ancient Greek and Roman civilizations. Grape seeds are rich in nutrients and proanthocyanidins, which have strong free radical scavenging properties, contributing to their high nutritional and therapeutic value. Grape seeds are a complex matrix containing 40% fiber, 16% oil, 11% proteins, and 7% complex phenols such as tannins. The conjugated and colonic metabolites of grape seed proanthocyanidins are responsible for their advantageous health effects. Studies have reported that grape seeds exhibit a broad spectrum of pharmacological properties against oxidative stress. Their potential health benefits include anti-oxidant, anti-microbial, anti-obesity, anti-diabetic, anti-neurodegenerative, anti-osteoarthritis, anti-cancer, and cardio- and eye-protective properties. Consumers are using grape seeds as a dietary supplement as a result of their awareness of the health advantages associated with proanthocyanidins. This review article summarizes the previous studies of the phytochemical compounds, pharmacological properties, and industrial applications of grape seeds.