Background/Objectives: Current urate-lowering therapies may cause serious side effects in patients. Thus, alternative treatments are needed to regulate uric acid (UA) levels in patients with hyperuricemia associated with kidney injury, and natural antioxidant sources have demonstrated utility in this field. For the first time, our study evaluated the effects of an extract of Dactylopius opuntiae insects on the levels of xanthine oxidase (XO) enzymes and synthetic free radicals in vitro and in vivo. Methods: Insects were bred and collected, and two different extracts (D1 and D2) were obtained. For both extracts, XO inhibition and radical scavenging assays were performed. Subsequently, serum purine levels and renal markers were quantified in male BALB/c mice who received a hyperuricemia induction using potassium oxonate, hypoxanthine, and gentamicin. Results: The D2 extract contained 18,037.7 µg/mL of carminic acid, inhibited 53.2% of XO activity at one concentration, and showed IC50 values of 18,207.8 and 5729.6 µg/mL against ABTS and DPPH radicals, respectively. D2 administration reduced serum UA and creatinine levels and prevented an increase in kidney weight and reduction in renal antioxidant capacity caused by hyperuricemia induction and allopurinol use in mice. Despite the satisfactory antioxidant results obtained in vitro, the D1 extract killed the animal models due to its citric acid content. Conclusions: The D2 insect extract can be used as an effective urate-lowering therapy when the increased level of serum uric acid is due to kidney damage.