This experiment was conducted to evaluate the effects of sodium butyrate (SB) supplementation on the growth performance of newborn calves. Forty healthy Holstein calves (4-d-old; 40 ± 5 kg of body weight [BW]) were randomly allocated to 1 of 4 treatment groups (n = 10). The control group was fed 0 g/d SB (SB0), while the other groups were supplemented with 15 g/d (SB15), 30 g/d (SB30), or 45 g/d (SB45) of SB, respectively. All calves were housed in individual hutches. Before the feeding experiment, all calves were fed 4 L colostrum within 1 h after birth and were given 2 more feedings of colostrum at 6 h (2 L) and 18 h (1 L) after birth. All calves were offered milk twice daily from d 2 to d 21, and then were supplied with milk powder (it was reconstituted into milk before each feeding) from d 22 to d 60 at weaning. The intended amount of SB was mixed with a small volume of the milk and fed first at each meal. Calves accessed water and the starter freely. Bodyweight, body length, body height, chest circumference, and pH of rumen fluid of the calves were measured at d 1, 14, 28, 42, and 60, while the dietary intake and fecal scores were recorded daily. The experiment was completed at d 60. Data were analyzed using the Proc Mixed model of SAS, with linear and quadratic polynomial contrasts tested using the CONTRAST statement. The appropriate coefficients for the CONTRAST statement of this study were obtained using PROC IML's ORPOL function. DMI, chest circumference, body length, and fecal score were not affected by SB (P > 0.05). Average daily gain of groups SB15, SB30 and SB45 were 11.4% (P < 0.01), 10.1% (P = 0.01), and 11.4% (P = 0.02) higher than that of SB0, with no significant differences among the SB groups. Feed to gain ratio was significantly decreased by SB (P < 0.01). pH value of rumen fluid was decreased linearly (P < 0.05) with the increased SB supplementation at d 14. These results indicated that supplementation with sodium butyrate can improve the growth performance of newborn calves.