The agreement comes after Braves outfielder Nick Markakis opted out of the 2020 season earlier this month.
A major league All-Star in 2014, Puig, 29, batted .267 in 149 games last season with the Cincinnati Reds and Cleveland Indians. He hit .297 with Cleveland after being acquired on July 30 and gave the Indians an infusion of power and energy, helping their ultimately fruitless surge to catch the Minnesota Twins for the American League Central title.
The boisterous right fielder was part of a wild fight between the Reds and Pirates mere hours before he was dealt to Cleveland as part of a three-team trade that sent right-hander Trevor Bauer from Cleveland to Cincinnati. Puig was suspended three games for his aggressive actions on what turned out to be his final day with the Reds.
Puig, who joined the Reds in a December 2018 trade with the Los Angeles Dodgers, has a career batting average of .277. Perhaps his best overall offensive season was in 2017, when he batted .263 with a career-high 28 home runs and 74 RBIs.
The National League East champion Braves were facing a depth problem in their outfield even after they signed Marcell Ozuna to a one-year, $18 million deal in the offseason.
Markakis opted out of the season before summer camp. Ozuna or Adam Duvall could be needed as the designated hitter in the shortened 60-game season.
The team's shortage of outfielders was highlighted when rookie Cristian Pache jammed his right ankle in Monday night's intrasquad game and was not available Tuesday.
"We're thin a little bit," manager Brian Snitker said Tuesday. "We started this thing feeling really good about the depth, and we've used all of it already, as I think a lot of teams have. We're stretched a little bit."
Duvall, who has been most productive against left-handers, and Markakis might have split time. Puig, who has a .285 career average against right-handers, will be expected to replace Markakis' production.
Puig, who defected from Cuba in 2012, was popular with Dodgers fans during his six years in Los Angeles for his colorful personality, home run trots and ability to throw runners out from right field. He made headlines away from the field when his Los Angeles home was burglarized multiple times.
At the ballpark, he was benched at times, and the team considered trading him long before it did because of his perceived lack of hustle or interest in following orders.
The Associated Press contributed to this report.