To evaluate the alleviative effects of saffron (Crocus sativus) petal extract (SPE) on growth performance, blood biochemical indices, antioxidant status, and immunity of heat-stressed broilers, 250 newly hatched male broiler chickens were randomly allocated to control diet (basal diet, two groups), or control diet supplemented with 300, 500, or 700 mg SPE/kg diet, with five replicates and 10 birds each. The broiler chickens, except one of the control groups, were exposed to heat stress (HS, 37 ± 1 °C, 55% relative humidity) for 6 h/day from day 25 to 42. Heat stress reduced body weight gain (BWG), feed intake (FI), and abdominal fat percentage, and increased feed conversion ratio (FCR, p