Background Rheumatoid arthritis (RA) is a long-term inflammatory disease linked to higher mortality, joint degeneration, and long-term disability. This study evaluated the anti-inflammatory, antioxidant, and immunomodulatory effects of Capsicum annuum (CAP) hydroethanolic extract and bee venom (BV) in Freund’s complete adjuvant (FCA)-induced RA in rats. Methods Forty-eight rats were divided into six groups: normal control (NC), RA control, and RA groups orally treated with methotrexate (MTX) (0.25 mg/kg), CAP (100 mg/kg), BV (0.25 mg/kg), and CAP (100 mg/kg) + BV (0.25 mg/kg). RA was induced by intradermal injection of FCA (100 μL/rat) into a footpad of the right hind paw at two consecutive days, and treatments were administered for 3 weeks. The study assessed serum rheumatoid factor (RF), anticyclic citrullinated peptide (ACCP) antibodies (ACPAs), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), oxidative stress markers such as lipid peroxidation, and antioxidant parameters including superoxide dismutase (SOD) and reduced glutathione (GSH). Additionally, mRNA expression of various genes (inducible nitric oxide synthase [iNOS], endothelial nitric oxide synthase [eNOS], interleukin-1β [IL-1β], TNF-α, matrix metalloproteinase-1 [MMP-1], matrix metalloproteinase-3 [MMP-3], and glutathione reductase [GR]) were analyzed, alongside histopathological evaluation. Results The data showed that CAP and/or BV significantly reduced serum inflammatory and oxidative stress biomarkers, enhanced the antioxidant defense system, and improved the histopathological changes of ankle joint. Gene expression analysis revealed downregulation of iNOS, eNOS, IL-1β, TNF-α, MMP-1, and MMP-3 gene expression, with upregulation of the GR gene expression. The combined CAP + BV treatment demonstrated the most potent antiarthritic effect. Conclusion CAP and BV exhibit promising potential for alleviating RA in rats, with their combined application showing the greatest efficacy. The antiarthritic effects may be mediated via suppression of oxidative stress and inflammation and enhancement of the antioxidant defense system in addition to the modulatory effects on MMP-1 and MMP-3 gene expression. Further clinical research is essential to evaluate their safety and effectiveness in human RA management.