Phlomis crinita is a medicinal plant commonly used in Algerian folk medicine as a remedy for ulcers, haemorrhoids and healing of wounds. The current study aimed to evaluate the anti-inflammatory and antioxidant effects of this plant and to provide a scientific basis for its use. Protein denaturation and membrane stabilization assays were used to assess the anti-inflammatory action in vitro. DPPH free radical-scavenging and reducing power tests were used to determine the antioxidant activity. The plant methanol extract exhibited potential anti-inflammatory activity, demonstrating its ability to prevent protein denaturation and stabilize the membrane of human red blood cells. It had IC50 values of 143.64 ± 2.94 and 119.63 ± 0.80 µg/mL, respectively, compared to diclofenac sodium (IC50 value of 60.60 ± 2.55 and 53.47 ± 0.93 µg/mL, respectively). P. crinita showed strong antioxidant DPPH scavenging activity (IC50 = 82.07±0.37 μg/mL) compared to ascorbic acid (62.48±0.56) and exhibited a strong reducing potential. The results suggested that the plant might be a potential candidate for oxidative stress prevention and inflammatory disease treatment.