This study evaluated the optimal concentrations of dietary Se for the productive and reproductive performance, tibial quality, and antioxidant status in duck breeders aged 23 to 49 wk. In total, 432 Longyan duck breeders aged 22 wk were allotted randomly to 6 treatments, each with 6 replicates of 12 individually caged birds. The experiment lasted for 27 wk, and birds were fed corn-soybean meal-based diets containing 0.11, 0.19, 0.27, 0.35, 0.43, or 0.51 mg Se/kg, respectively. The tested dietary Se levels did not affect egg production and tibial quality of duck breeders. The Se contents of the shell, yolk or albumin, whole egg, and the fertility of set eggs increased in a linear and quadratic manner (P < 0.05) in response to the increased dietary Se level, whereas the yolk malondialdehyde (MDA) and embryonic mortality decreased. The activities of glutathione peroxidase 3 (Gpx3) in plasma and Gpx1 in the erythrocytes and livers of breeder ducks increased in a linear and quadratic manner (P < 0.05) in response to increased dietary Se levels, whereas the total superoxide dismutase (T-SOD) activity increased and the MDA concentration decreased in the liver. The activity of Gpx3 in the plasma and Gpx1 in the erythrocytes and livers of newly hatched ducklings increased linearly (P < 0.01) with the increase in Se level, whereas the T-SOD activity and MDA concentration did not change. In conclusion, diets containing 0.27 mg Se/kg led to the highest egg fertility and hatchability in Longyan duck breeders, and using levels >0.19 mg Se/kg diet enhanced the antioxidant capacity in breeders and their offspring. The regression model indicated that dietary Se levels 0.19, 0.27, 0.28, 0.24, and 0.30 mg/kg are optimal levels to obtain maximum Se deposition efficiency in eggs, egg fertility, Gpx1 activity in erythrocytes and liver in duck breeders, and plasma activity of Gpx3 in newly hatched ducklings, respectively.