Braun was yet to feature in the current season and had hinted towards retirement during spring training this year. The 2011 National League MVP made it official on Tuesday in a video the Brewers posted on Twitter.
"While it's impossible to summarize my emotions right now, what I feel most is one simple thing — gratitude," Braun said.
"I have weighed this decision for many months. While I still love this game very much, the time is right for me to retire from my playing days," Braun said in a statement released by the team.
The 37-year-old batted .296 with 352 home runs and 1,154 RBIs. He ranks second among Brewers in RBIs (1,154), extra-base hits (809), total bases (3,525), and doubles (408). He ranks third in runs (1,080), hits (1,963), triples (49), stolen bases (216), and walks (586). He is fourth in games played (1,766).
Braun became a free agent after the Brewers declined to exercise a $15 million mutual option in his contract last October. The six-time All-Star had a career-low of .233, managed to hit eight home runs and 26 RBIs in 39 games last season. All this was while he was dealing with a back issue.
Braun was one of baseball's best hitters from 2007-12 but was never the same after he was suspended midway through the 2013 season for using performance-enhancing drugs. He acknowledged that he took banned substances while rehabilitating an injury and apologized.
From 2014 on, Braun never played more than 144 games in a season. He reached the 30-homer mark once after topping 30 homers five times in his first six years, including an NL-leading 41 in 2012. Still, he remained a key contributor for the Brewers.
"I always thought that the way Ryan's last six or seven years went, he should be incredibly proud with how those years went," Brewers manager Craig Counsell said.
"He should be incredibly proud of that. At that point, he had a story to write, he didn't know how it was going to go and I think he wrote a great story and that he should be proud of that," Counsell added.
Braun was teammates with Counsell early in his career before eventually playing for him.
"What I always tell Ryan is, I always joke with him that maybe besides your mom and your dad, I have seen you play baseball probably more than anyone in the world. I was there for every game throughout his career. I got a close seat for a vast majority of them. Watching him play was definitely an honor," Counsell said.
The Brewers selected Braun with the fifth overall pick in the 2005 amateur draft out of Miami. He was named NL Rookie of the Year in 2007 and ranked in the top 15 in the MVP voting every year from 2008-12. He finished second in the MVP balloting in 2012 and third in 2008.
The Brewers reached the postseason five times during Braun's career (2008, 2011, and 2018-20).
The Brewers plan to honor Braun at a pregame ceremony on September 26 before they face the New York Mets in their regular-season home finale.
(With AP inputs)