Plums contain a large amount of biologically active compounds such as flavonoids and anthocyanins, which display high potential as a resource for the development of functional foods. Collagen stick jelly supplemented with various fruit concentrates has recently been developed due to the beneficial effects of collagen on skin aging and joint health and its antioxidant effects. This study examined the physicochemical, sensory qualities, and antioxidant activity of collagen stick jelly made with plums grown in Uiseong. Plum collagen jelly was divided into four groups including plum concentrate containing stevia with purified water (WC0), plum concentrate with purified water (WC1), plum concentrate containing stevia with plum juice (JC0), and plum concentrate with plum juice (JC1). The results showed that JC had a higher L * (nominal) value and b * (yellow degree) value than other jellies. The total sugar content of WC was higher than that of JC, which may have been influenced by the addition of plum concentrate. JC, with the addition of plum concentrate, showed higher polyphenol and flavonoid contents as well as antioxidant potential, including radical scavenging activity and reducing power compared to the jellies supplemented with purified water. The sensory qualities of JC1 indicated that among all the jellies, it had the best taste, flavor, and overall likeability with high sweetness and a plum flavor. This study provides a perspective on use of Korean plums as a potential dietary supplement.