probiotic in poultry diets, no evidence has been found to support the use of Paenibacillus polymyxa in the diet of Japanese quails. This study examined the e􀀀ects of supplementing growing Japanese quail with a mixture of Bacillus coagulans and P. polymyxa (Bc+Pp) on their growth performance, antioxidative activity, immunological status, digestive enzymes, caecal microbiota, and blood chemistry. Methods: Two hundred 1-week-old meat-type quail chicks were divided into four groups at random; five pens, each containing ten birds. These birds were provided with a basic feed as a control group, or a feed diet treated with 0.5, 1.0, and 1.5mg kg−1 of Bc+Pp mixture (1:1). Results: According to the findings, the growing quail’s growth performance was significantly (P<0.05) enhanced by supplementing the Bc+Pp mixture. Body weight and body weight gain were boosted significantly (P = 0.0002, P = 0.0003) by Bc+Pp mixture supplementation at 5 weeks and 1–5 weeks. In contrast, feed consumption showed a non-significant di􀀀erence (P = 0.8082) with the treatments within 1–5 weeks. Moreover, the feed conversion ratio was significantly (P<0.05) boosted (P = 0.0137) with the supplementation of the Bc+Pp mixture. Furthermore, Bc+Pp mixture supplementation provided a significant boost in carcass traits, especially liver, gizzard, and giblet percentage (P = 0.0112, P = 0.0976, and P = 0.0028). The current result showed a significant (P<0.05) increase in total protein, albumin, and globulin with supplementation of the Bc+Pp mixture. Moreover, the treatment significantly (P<0.05) reduced total cholesterol, triglycerides, and low-density lipoprotein. Superoxide dismutase, total antioxidant capacity, reduced glutathione, and glutathione peroxidase were significantly (P<0.05) improved by supplementation of the Bc+Pp mixture. Furthermore, the digestive enzymes were significantly (P<0.05) improved, and the total bacterial and lactic acid bacteria counts were significantly (P<0.05) augmented, whereas the counts of Salmonella spp., Escherichia coli, total coliform, and Enterococcus spp. were significantly (P<0.05) decreased with dietary bacterial mixture treatments. Discussion: In conclusion, supplementing growing Japanese quail with a mixture of Bc+Pp has a positive impact on their growth performance, antioxidative status, immunological response, digestive enzymes, and caecal microbiota.