The present research experimented with the view of observing the effect of supplementing purified fish oil (FO) on growth performance, organ weight, meat quality, along with blood profile of broilers. The experiment was conducted upon 1600 male Ross 308, each aged 1 day, broiler strains with an average body weight of 43.15 ± 1.35 g were randomly allotted into four dietary treatment groups where CON, basal diet; TRT1, CON + 0.05% FO; TRT2, CON + 0.10% FO; and TRT3, CON + 0.15% FO respectively. Each treatment group consisted of 20 replication pens, with each pen containing 20 broiler chicks. The 4‐week long experiment was divided into two phases. The first phase (Days 7–21), the second phase (Days 22–35) and the overall (Days 7–35). On Day 21, the body weight of broilers in TRT2 and TRT3 was higher than the control. Increasing doses of purified FO supplementation showed a linear (p < 0.05) increase in body weight on Day 21. At the end of Phase 1, FO supplementation improved the body weight gain (BWG) of TRT2 and TRT3 group birds compared to CON. Increasing doses of FO supplementation increased the BWG linearly in all phases. Increasing doses of FO increased chicks' breast muscle weight with the highest value in the TRT3 group. Moreover, liver weight was linearly decreased in FO supplementation groups compared to the CON group. Abdominal fat was linearly decreased in FO supplemented groups. FO supplementation caused the lowest cholesterol and triglyceride in TRT3 than the CON group with a linear reduction. Low density lipoprotein (LDL) cholesterol was reduced by FO supplemental groups. In addition, FO supplementation increased the red blood cell (RBC) in the TRT3 group compared to the CON group. In conclusion, refined FO increased BWG, breast muscle weight and RBC and reduced cholesterol, triglycerides and LDL in broilers' blood.