Halophytes are salt tolerating plants that grow in variable habitats, such as deserts and steppes. Chenopodiaceae and Amaranthaceae are two families widely prevailing in Saudi Arabia. They include plenty of previously unexplored halophytes. In a research program aimed at exploring the phytochemical content and biological potential of Qassim region halophytes; the current study presents phytochemical analysis as well as assessment of the antioxidant and antimicrobial activity of the five halophytes: Agathophora alopecuroides var. papillosa, Atriplex leucoclada, Halothamnus bottae, Salsola villosa, and Salicornia persia ssp. Iranica. Results of qualitative phytochemical analysis indicated the presence of saponins, tannins, sterols, carbohydrates, and flavonoids in all tested species. The comparison of the phenolic content of the five species revealed the highest total phenolics content and total flavonoids content in S. villosa (135.2 mg GAE/g and 18.2 mg QE/g, respectively) and A. leucoclada (134.1 mg GAE/g and 21.2 mg QE/g, respectively). Investigation of the antioxidant potential demonstrated the highest activity of H. bottae followed by S. villosa (IC₅₀ 263.7 and 290.7 μg/mL, respectively). Additionally, screening of the antimicrobial activity revealed potent activity of Salicornia persia, H. bottae, and S. villosa against Staphylococcus aureus while none of the tested extracts displayed antifungal activity against tested fungal species.