Anthopoulos, who is taking on a new role as president of baseball operations as part of the deal, is now under contract through 2024. Snitker and his coaching staff are in place through the 2021 season.
"I am very pleased that Alex will be leading the Atlanta Braves' baseball operations for years to come," chairman Terry McGuirk said. "Since he joined the organization, Alex has continued the winning tradition that Braves fans have come to expect."
Snitker, 64, has been the Braves manager since 2016. He's led the club to playoff berths the last two seasons, though Atlanta lost in the NLDS both years. In 2018, Snitker was named National League Manager of the Year.
"Winning consecutive division titles illustrates the leadership and impact of Brian and his staff," Anthopoulos said. "We are happy to know they will be leading the Braves through the 2021 season."
Anthopoulos, 42, has been with the Braves since 2017. The club underwent a swift improvement under his stewardship, going from 72 wins in 2017 to 90 in 2018 to 97 last season. He previously served as the Toronto Blue Jays general manager from 2010 to 2015, leaving the organization after winning Sporting News' Executive of the Year Award.
The Braves enter 2020 expected to compete for a third straight NL East championship in a tough division. The defending champion Washington Nationals, Philadelphia Phillies and New York Mets each have enough talent to feel like contenders.