Date palm (Phoenix dactylifera L.) trees are largely cultivated across the Algerian oases; they are principal sources of remuneration and the economic basis for residents of these areas. Date palm fruits are rich sources of essential nutrients, vitamins, minerals, and dietary fibers, with many potential health benefits, yet there are few studies on the chemical composition and biological properties of date palm seed oil. In this study, we present an in-depth characterization of the biochemical composition and antioxidant properties of date palm seed oil (DPSO) produced in Algeria. DPSOs of eight Algerian cultivars, Arechti, Degla-Baida, Deglet-Nour, Ghars, Haloua, Itima, Mech-Degla, and Tentbouchet, were investigated to determine their biochemical compositions and antioxidant properties. The results highlight the potential of DPSO as an alternative food and a natural resource, thanks to several important compounds having high antioxidant capacity. In particular, fatty acids and triacylglycerol (TAGs) analyses showed that oleic (42.74-50.19%), lauric (18.40-22.2%), and myristic (8.83-10.17%) were the major fatty acids, while 1-myristoyl 2-oleoyl 3-linoleoyl glycerol, 1-linolenoyl 2-oleoyl 3-linoleoyl glycerol, 1-2-linolenoyl 3-linoleoyl glycerol, and 1-linolenoyl 2-myristoyl 3-linoleoyl glycerol were the major TAGs. Biophenols and tocopherols analyses revealed the presence of important compounds, such as catechin (22.04-24.92 mg/kg), vanillin (10.67-23.98 mg/kg), and alpha-tocopherol (443.59 mg/kg), at high remarkable levels. Therefore, a comparison with the literature data concerning other seed oils, including olive oil, confirms that DPSO can be considered a high-quality oil, from a biochemical and biological point of view.