The use of post-production and post-process by-products is an activity that is in line with the latest trends in the fruit industry. Obtaining new nutrients from them can be of great importance not only for the food industry, but also for pharmaceuticals. Cornelian cherry seeds can be one of the novel sources rich in functional ingredients with a wide range of applications in the food, nutraceutical, pharmaceutical, and cosmetic industries. Furthermore, there is currently a dynamic increase in interest in oilseeds, not only for the production of vegetable oils and oilseed meal, but also due to the growing demand for renewable energy. Cornelian cherry seeds can be a source of innovative oil with high nutritional and health-promoting properties and a high energy value. The published results of research prove the richness of attractive fatty acids, as well as many health-promoting compounds. This review discusses the nutritional and phytochemical profile, as well as the biological activity exhibited by cornelian cherry seed oil. In addition to its undoubted functionality, extensive research is still needed to promote its use at the industrial level to take advantage of all the benefits of its chemical composition.