This study assessed the effects of varying concentrations of clove essential oil (CEO) on broiler chickens' growth metrics, cecal microbiota composition, and blood serum metabolites, positioning CEO as a potential substitute for antibiotic growth enhancers. A total of 250 one-day-old Ross 308 chicks were evenly distributed into five groups, with each group comprising 50 chicks. The control group, G1, received a basal diet devoid of any supplements; G2 was fed a basal diet plus 20 mg/kg of avilamycin; groups G3, G4, and G5 were administered 100, 200, and 300 mg/kg of CEO, respectively. The study documented a direct correlation between CEO dosage and the birds' growth efficiency. Notably, groups G3 and G4 exhibited significant (P < 0.05) improvements in both weight gain and feed conversion ratio compared to the other groups, without a change in feed consumption. While carcass quality remained consistent across the groups, significant increases (P < 0.05) in the weights of the intestine and bursa were observed in G4 and G3, respectively. Addition of CEO markedly elevated (P < 0.05) serum levels of immunoglobulin (IgA) and high-density lipoprotein (HDL), while concurrently reducing levels of low-density lipoprotein (LDL) and total cholesterol. Additionally, CEO use notably enhanced the cecal microbiota by augmenting Lactobacillus spp. populations and reducing (P < 0.05) E. coli numbers in the ileum of groups G4, G3, and G2. The outcomes suggest that clove essential oil supplementation could bolster growth, immunity, and intestinal health in broiler chickens, offering a viable alternative to antibiotic use.