This investigation sought to assess the impact of incorporating garlic powder and thyme leaves on the growth performance, carcass attributes, specific hematological parameters, and antioxidant capacity in Japanese quails throughout the growth phase (7–42 days). A total of 225 seven-day-old Japanese quail chicks were allocated into three distinct dietary treatments (75 birds/treatment) with three replicates for each treatment (25 birds/replicate). The chicks were systematically assigned to the following treatments: T1: Administered a basal diet devoid of any additives (control). T2: Administered a basal diet augmented with 10 g of garlic powder per kg of feed. T3: Administered a basal diet augmented with 10 g of thyme leaves per kg of feed. The findings from the statistical analysis revealed that body weight, weight gain, and feed conversion efficiency exhibited significant enhancement (P ≤ 0.05) commencing at 21 days of age and persisted until 42 days of age (the conclusion of the experiment). Nevertheless, no significant discrepancies were observed among treatments regarding feed intake. The findings further indicated that levels of total protein, albumin, globulin, and glucose experienced significant elevation in diets supplemented with garlic powder and thyme leaves. Conversely, the inclusion of these additives significantly (P ≤ 0.05) diminished cholesterol levels in the blood of quails within the experimental groups in comparison to the control group. Additionally, a marked reduction in total lipid levels was noted in the additive groups relative to the control group. The study also demonstrated a notable decrease in malondialdehyde (MDA) concentration alongside a significant increase in glutathione (GSH) levels within the additive groups. In summary, the incorporation of garlic powder and thyme leaves into the diet positively influenced growth performance, select blood parameters, and the antioxidant status of Japanese quails.