The aim of this study was to determine the effect of different dietary fat on carcass traits in Japanese quail (Coturnix coturnix japonica). A total of 168 7-week-old Japanese quail (48 males and 120 females) were used in this study. They were evenly distributed into 4 treatment groups, with 3 replicates per group containing 4 males and 10 females each. The birds were fed a basal diet with different fats (sunflower, flax, corn, and fish oils) at a 3% level for 13 weeks. On the last day of the experiment, 12 birds were randomly selected from each treatment group (6 males and 6 females) and slaughtered to determine carcass characteristics included in this study, which were carcass weight, dressing percentage with or without giblets, and the relative weights of heart, liver, gizzard, thighs, wings, breast, back, neck, and abdominal fat. Our results indicated that supplementing the diet of quail with fish oil and flax oil resulted in significant improvements concerning body weight, carcass weight, dressing percentage with or without giblets, and relative weights of the heart, liver, gizzard, thigh, and breast, and a significant decrease (p < 0.05) as regards the relative weights of the wings, back, and neck compared to treatments of sunflower oil and corn oil. However, T4 (fish oil) surpasses other treatment groups (T1, T2, and T3) in relation to all carcass parameters involved in this experiment. Overall, the results reveal that adding fish and flax oils to the diet of Japanese quail have a significant effect on carcass efficiency. Therefore, fish and flax oils could be used as a good tool for improving the carcass yield of quails.