Probiotics are used at different stages of gestation to promote reproductive performance in sows. This study investigated the effect of Bacillus subtilis QST 713 supplementation during late gestation in multiparous sows on different reproductive parameters. On day 85 of gestation, 115 multiparous healthy Landrace Yorkshire sows were randomly assigned to two groups with equal parity numbers. The control group (58 sows) was fed with basal diets, and the probiotic group (57 sows) was fed with basal diets +1010 colony-forming unit (CFU) B. subtilis QST 713 from day 85 to parturition. Back fat thickness on days 85 and 110, number of total born, number of born alive, stillbirth and mummy rates, individual birth weight, litter birth weight, within-litter variation of piglet birth weight, and postpartum vaginal discharge duration were recorded and compared between the two groups. The number of total born, number born alive, back fat thickness of sows before farrowing, litter weight, within-litter variation of piglet birth weight, and postpartum vaginal discharge duration were similar in both groups (p > 0.05). Dietary supplementation with B. subtilis QST 713 decreased the stillbirth rate (3.96 vs. 6.39%, p = 0.046) and born dead rate (5.12 vs. 8.57%, p = 0.035) and increased the birth weight of piglets (1552.78 vs. 1506.15 g, p = 0.049). Daily supplementation with 1010 CFU of B. subtilis QST 713 during late gestation in multiparous sows could increase reproductive performance by increasing birth weight and decreasing stillbirth rate.