Halophytes are plants with significant economic potential for their nutritional and medicinal properties. High-performance liquid chromatography (HPLC) was used to identify the phenolics and flavonoids compounds of six halophyte plants (Spergularia marina, Suaeda aegyptiaca, Arthrocnemum fruticosum, Halophila stipulacea, Halodule uninervis, and Thalassodendron ciliatum) ethanol extracts, additionally, physiochemical parameters such as total ash, water-soluble ash acid in soluble ash, total carbohydrates, soluble carbohydrates, total nitrogen, and total protein were estimated. The results showed that nineteen phenolic and eleven flavonoid compounds were confirmed by HPLC qualitatively and quantitatively in ethanol extracts of all plants. The major compounds were chlorogenic, gallic, vanillic, naringin, and naringenin. Also, evaluation of their anticancer activities against cell lines such as pancreatic carcinoma (PA1), lung cancer (A549), prostate cancer (PC3), and colon cancer (Caco2) was carried out. The anticancer activities of A. fruticosum site (1), S. marina, and A. fruticosum site (2) extracts demonstrated the highest effective anticancer activities with IC50 values of 74.38 ± 3.04, 85 ±  2.11, and 88.922 ± 0.735 µg/mL, respectively, against human cancer cell lines (caco2) than other plants that were understudied. As a result of this research, halophyte plants can be viewed as a potential medicinal ingredient.