Abstract This study was conducted to identify the nutritional value of corn from US, Brazil (BRZ), and Argentina (ARG). A total of 96 nursery pigs [initial body weight (BW) = 8.79 kg] were used in the feeding trial for 25 days and fed one of three diets with sole corn source (3 treatments, 8 replicates, 4 pigs/pen) in a randomized complete block design. The BW and feed consumption of pigs were measured every week to calculate the average daily gain (ADG) and gain to feed ratio (G:F). Twelve barrows (average BW = 23.7 ± 2.6 kg) housed in metabolic crates were fed one of three experimental diets with corn as a sole energy source to determine the energy value of the corn. The pigs had 7 d of adaption, followed by 4 d of fecal and urine collection with a total collection method for two periods (3 treatments, 8 replicates, 1 pig/crate). Ten ileal-cannulated pigs (average BW = 20 kg) were fed one of four diets, such as corn starch-based diet with different corn sources, and a nitrogen-free diet supplemented with titanium dioxide, in a 4 x 4 Latin Square design (4 treatments, 10 replicates, 1 pig/crate) to determine the ileal digestibility of amino acids by using an indicator method. The ileal-cannulated pigs had 5 days of adaptation, followed by 2 days of ileal digesta collection. Pigs were fed the diets at three times of maintenance energy requirement according to NRC (2012) in two equal meals daily. Pigs fed the US corn diet showed greater (P < 0.05) ADG and G:F for d 0 to 7 than those of pigs fed ARG diet by 13% and 16%, respectively, and tended to have greater (P < 0.10) ADG and G:F for d 0 to 7 than those of pigs fed BRZ corn diet. Pigs fed the US corn diet had greater (P < 0.05) G:F for the overall period (d 0 to 25) than that of pigs fed the BRZ diet by 4% and had a tendency of greater (P < 0.10) G:F for the overall period than that of pigs fed the ARG diet. Dietary corn sources have no significant influence on the standardized ileal digestibility of amino acids and crude protein in pigs. The metabolizable energy values for US, ARG, and BRZ were 3,297 kcal/kg, 3,297 kcal/kg, and 3,240 kcal/kg, respectively. The net energy values for US, ARG, and BRZ were 2,644 kcal/kg, 2,636 kcal/kg, and 2,592 kcal/kg, respectively. However, dietary corn sources had no significant differences in metabolizable energy and net energy values. In conclusion, dietary US corn improved the growth performance of nursery pigs through the improved energy values in pigs compared with the Brazil and Argentina corns.