This study aimed to assess the effect of supplementing Arbor Acre broiler chick diets with a blend of peppermint and clove oils on growth efficiency, blood indicators, and intestinal microbial communities. In a randomized experimental design, 250 unsexed, one-day-old Arbor Acre broiler chicks were allocated into 5 groups. Each group included 5 replicates, each containing 10 birds. The control group administered a basal diet devoid of oils, whereas the remaining groups were provided with meals enriched with 150, 300, 450, or 600 mg/kg of the oil blend. The findings indicated significant variations (P ≤ 0.05) among the treatment groups during weeks 3 to 6—supplementation with the oil blend led to increased body weight (BW) and body weight gain (BWG). Compared to the control, birds receiving the oil consumed less feed intake (FI) and exhibited an improved feed conversion ratio (FCR). Additionally, the oil-supplemented diets significantly (P ≤ 0.05) decreased abdominal fat and altered the relative weights of the gizzard, giblets, spleen, thymus, and bursa. Except for hemoglobin, all hematological indicators were substantially influenced by the oil supplementation. Biochemical analysis revealed significant reductions (P ≤ 0.05) in serum levels of alanine transaminase (ALT), aspartate transaminase (AST), urea, creatinine, cholesterol, triglycerides, low-density lipoprotein (LDL), and glucose. Conversely, total protein, albumin, globulin, and high-density lipoprotein (HDL) levels significantly increased (P ≤ 0.05). Oil supplementation also enhanced immune response and antioxidant enzyme activities, as evidenced by significant increases (P ≤ 0.05) in total oxidant capacity (TAC), superoxide dismutase (SOD), reduced glutathione (GSH), and catalase (CAT), along with a notable decrease in malondialdehyde (MDA) levels. Moreover, birds fed diets containing the oil blend exhibited changes in digestive enzyme activity and blood mineral levels. Microbiological assessments showed decreased counts of Salmonella and E. coli in the oil-treated groups. In conclusion, dietary supplementation with peppermint and clove oils improved growth performance, enhanced gut microbiota balance, and positively influenced carcass traits and biochemical markers in broiler chickens.