Ziziphus jujuba has many health-beneficial properties due to the presence of saponins, jujubogenin, obelin lactone, etc., and are mostly used in treating neurodegenerative, gastroenteric, and heart diseases. In this context, seeds of jujube were collected, washed, dried, and ground into fine powder. Seed powder was extracted using different solvents (i.e., 70% ethanol, 80% methanol, DMSO, water) followed by ultrasonication. Polyphenol content of the crude jujube seed powder and its different extracts was studied using the Folin Ciocalteu Method, flavonoid content was determined using aluminum chloride colorimetric assay, and antioxidant activity was studied by DPPH radical scavenging activity. Results showed that 70% ethanol extracted 67.14 g per Quercetin standard. The highest polyphenol content of 3.575 mg GAE and a radical scavenging activity of 77.96% was obtained in 0.1 g crude seed powder. Crude seed powder showed antibacterial activity against two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa and two Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. Though being an agro-waste, jujube seed can be used for medicinal purposes and as a bioactive component in protecting gut health and can also be used as a biodegradable food packaging material promoting sustainable waste management.