Salicornia is a halophyte plant that has been used in traditional medicine for the treatment of scurvy, goiter, and hypertension. It is commercialized in Europe and Asia as fresh salads, pickled vegetables, green salt, or tea powder. This work is the first to assess the potential anti-obesity and anti-dyslipidemic effects of Salicornia arabica decocted extract (SADE). SADE was characterized by its significant in vitro radical scavenging activity (using DPPH and ABTS assays). The effect of SADE on food intake, weight loss, serum biochemical parameters, liver and kidney weights, adiposity index and on liver histology was investigated in the Tunisian gerbil Psammomys obesus (P. obesus), which is recognized as a relevant animal model of human obesity and diabetes. P. obesus animals were firstly randomly divided into two groups: the first received a natural low-calorie chow diet (LCD), and the second group received a high-calorie diet (HCD) over 12 weeks. On day 90, animals were divided into four groups receiving or not receiving SADE (LCD, LCD + SADE, HCD, and HCD + SADE). If compared to the HCD group, SADE oral administration (300 mg/kg per day during 4 weeks) in HCD + SADE group showed on day 120 a significant decrease in body weight (−34%), blood glucose (−47.85%), serum levels of total cholesterol (−54.92%), LDL cholesterol (−60%), triglycerides (−48.03%), and of the levels of hepatic enzymes: ASAT (−66.28%) and ALAT (−31.87%). Oral administration of SADE restored the relative liver weight and adiposity index and significantly limited HCD-induced hepatic injury in P. obesus. SADE seems to have promising in vivo anti-obesity and anti-dyslipidemic effects.