Psoriasis is a chronic inflammatory skin disorder involving oxidative stress and immune dysregulation. Given the limitations and adverse effects of conventional therapies, interest in natural treatments with anti-oxidant and immunomodulatory properties is increasing. This study aimed to comprehensively evaluate the therapeutic potential of Galium verum extract in an imiquimod-induced rat model of psoriasis. The extract was chemically characterized by HPLC and evaluated for anti-oxidant activity using DPPH, ABTS, and FRAP assays. Molecular docking studies targeted psoriasis-related proteins (IL-17, IL-22, IL-23, JAK2, MAPK2, NF-κB, STAT3), revealing strong binding affinities for rutin and quercetin, the extract’s dominant bioactives. In vivo, 18 Wistar albino male rats were divided into control (CTRL), psoriasis (PSORI), and psoriasis treated with Galium verum (PSORI + GV) groups. A seven-day topical application of 5% imiquimod cream was used for the induction of psoriasis. The PSORI + GV group received 250 mg/kg Galium verum extract orally for 7 days. Morphometric and redox analyses were performed. Histological and morphometric analyses showed reduced epidermal thickness, inflammation, and collagen content. Redox analysis revealed lowered oxidative stress biomarkers and enhanced anti-oxidant defenses. These findings suggest that Galium verum extract exerts anti-psoriatic effects through antioxidative and immunomodulatory mechanisms, supporting its potential as a natural adjunct therapy for psoriasis.