A feeding experiment was carried out to examine the effect of dietary sodium selenite (SS) supplementation on pigeon squabs. A total of 864 paired pigeons were randomly and equally distributed into four groups with three replicates. Each group was given a basal diet either unsupplemented (T1) or supplemented with 0.5, 1.0, or 1.5 mg/kg of SS in feed (T2–T4). Diet had no significant effect on the final body weight of squabs (P > 0.05). However, during days 8–14, body weight gain (BWG) in SS supplemented groups was lower than the control group (P < 0.05), while BWG was higher than controls from days 15–21 (P < 0.05). Squabs fed the basal diet without SS supplementation displayed lower selenium content in chest and leg muscle (P < 0.05). Glutathione peroxidase 4 (GPx4) mRNA levels were lower in liver, ovary and testis tissue in controls (P < 0.05), while growth hormone (GH) mRNA levels in liver were higher in controls (P < 0.05). These results suggest dietary SS supplementation had potential effect on growth performance during the later growth period (days 15–21). Furthermore, dietary SS supplementation increased the selenium content in muscle and affected the expression of GPx4 and GH.Highlights The dietary selenium supplementation affected the body weight gain of the squabs. Increasing selenium supplementation in diet improved the selenium content in muscle. Increasing selenium supplementation in diet affected the expression of GPx4 and GH.