This experiment was conducted to investigate the effects of olive leaf (OL) on the performance, abdominal fat pad and some ileal bacterial population of Cobb broiler chickens. A total number of 400 day-old chicks were randomly distributed into floor pens and reared under the same condition until 14 days of age. On day 14, each pen was randomly assigned to one of the five experimental treatments with four replicates of 20 male and female chicks. The dietary treatments were consisted of a control group which fed basal diet without OL entire period of the study and groups 2 to 5 that fed diets supplemented with 0.25, 0.50, 0.75 and 1.00% OL powder, respectively. On days 21 and 42 of the experiment, ileal digesta samples were collected under the sterile condition to evaluate ileal bacterial population. The results indicated that birds fed diets containing various levels of OL, had higher body weight gain (except for 1.00% OL) and lower feed conversion ratio compared to that of the control group. Dietary inclusion of OL resulted in a higher count of Lactobacillus sp. compared to the control group on 42 days of age, while Escherichia coli count significantly was not influenced. The abdominal fat pad was lower in birds fed OL supplemented diets. In conclusion, findings of the current experiment showed that the OL had positive effects on feed conversion ratio, abdominal fat pad deposition and ileal bacterial count of broiler chickens.