Erodium guttatum is widely used in folk medicine in many countries to treat various ailments such as urinary inflammation, diabetes, constipation, and eczema. The aim of this study is the determination of mineral and phenolic compounds of E. guttatum extracts as well as the investigation of their antidiabetic and antioxidant properties. The mineral composition was determined by the methods of inductively coupled plasma atomic emission spectroscopy analysis. Phytochemical contents of total polyphenols, total flavonoids, and catechic tannins were estimated by colorimetric dosages. The phenolic composition was identified by high-resolution mass spectrometry (HRMS) analysis. The antioxidant activity of E. guttatum extracts was measured in vitro by five methods (DPPH, ABTS, FRAP, H2O2, and xanthine oxidase) and in vivo by assaying the malondialdehyde marker (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). The obtained results showed that the root plant material is rich in minerals such as k, Ca, and Mg. The methanolic extract of E. guttatum is the richest in polyphenols ( 389.20 ± 1.55 mg EAG/gE), tannins ( 289.70 ± 3.57 mg EC/gE), and flavonoids ( 432.5 ± 3.21 mg ER/gE). Concerning the ESI-HRMS analysis, it showed the presence of numerous bioactive compounds, including shikimic acid, rottlerine, gallic acid, and vanillic acid. Moreover, the aqueous and alcoholic extracts of E. guttatum exhibited antiradical and antioxidant activity in five tests used, with the best effect of the methanolic extract. Moreover, findings showed that in vivo investigations confirmed those obtained in vitro. On the other hand, E. guttatum showed important antidiabetic effects in vivo. Indeed, diabetic mice treated with extracts of E. guttatum were able to significantly reduce MDA levels and increase the secretion of enzymatic and nonenzymatic antioxidants (SOD, CAT, and GSH, respectively). However, the antioxidant activity of the extracts might be attributed to the abundance of bioactive molecules; as results, this work serves as a foundation for additional pharmacological research.