He received 27 first-place votes and three seconds for 144 points. Fellow international phenom Juan Soto of the Washington Nationals got two firsts and 89 points, and Los Angeles Dodgers pitcher Walker Buehler was next with one first and 28 points.
"First of all, I would like to give thanks to God, my family, my parents and to all my teammates who've always supported me from the first day that I got the call to the big leagues," Acuna said in a statement released by the team. "This award represents all our hard work as a team this season."
A 20-year-old Venezuela native, Acuna signed with the Braves as an international free agent in 2014. After hitting .325 with 21 home runs across three different minor league levels in 2017, he entered the 2018 season ranked as the top prospect in baseball by ESPN's Keith Law.
Acuna is the eighth Braves player to win Rookie of the Year and first since Craig Kimbrel in 2011. He's the first Braves position player to win the award since Rafael Furcal in 2000.
Despite hitting .432 with four home runs in 16 spring training games, Acuna was optioned to Triple-A to start the season, a move that was criticized by those who believed the Braves demoted the young star for contractual reasons. Acuna was called up April 25 and made his big league debut against the Cincinnati Reds later that day, going 1-for-5 with a pair of strikeouts. At the time of his promotion, Acuna became the youngest player in the majors, a title he would soon cede to Soto.
After the All-Star break, Atlanta manager Brian Snitker moved Acuna into the leadoff spot, where the rookie outfielder was a catalyst for a surprising Braves team that won the National League East. Batting exclusively at the top of the order, Acuna thrived, hitting .322 with 19 home runs in 68 games during the second half of the season; his eight leadoff home runs were the second-most by a rookie in a season in MLB history.
In August, Acuna became the youngest player ever to homer in five consecutive games, and was named NL Rookie of the Month. Soto, his main competition for Rookie of the Year, won the monthly award in June, July and September.
Although the speedy Acuna is widely considered a better defender than Soto and a more complete player, the two international phenoms put up nearly identical offensive numbers in their debut seasons, creating one of the tightest Rookie of the Year races in recent memory.
In 111 games, Acuna hit .293 with 26 home runs and 64 RBIs, while posting a .917 OPS. In 116 games, Soto batted .292 with 22 homers and 70 RBIs, with a .923 OPS. According to FanGraphs, both players had an identical 3.7 wins above replacement.
Buehler, a 23-year-old right-hander, was 8-5 with a 2.62 ERA in 23 starts and one relief appearance.
ESPN Stats & Information and The Associated Press contributed to this report.