The two-time reigning MVP will make $228 million over the duration of the extension, his agent Alex Saratsis told ESPN's Adrian Wojnarowski. Antetokounmpo has an opt-out after the 2024-25 season.
Including his $27.5-million salary for the 2020-21 campaign, the 26-year-old stands to make just under $256 million over the next six campaigns.
Antetokounmpo's deal also contains a 15% trade kicker, The Athletic's Shams Charania reports. Trade kickers represent extra money a player can receive if he's dealt.
"This is a big moment for me and my family and I want to thank the Bucks organization for believing in us. You took a chance on us eight years ago and now putting my signature on a contract like this is unreal - but it's all because of hard work," Antetokounmpo said in a statement.
"This is my home and I'm going to continue working hard and do my best to make the Bucks, our fans, and the city proud," he added.
The Bucks had until Dec. 21 to sign their star to the super-max extension. Otherwise, both sides wouldn't have been able to reach an agreement until next summer, when Antetokounmpo could've left Milwaukee empty-handed by departing as an unrestricted free agent.
Tuesday's announcement dashes the hopes of rival franchises like the Toronto Raptors and Miami Heat that appeared to tailor their organizational strategies to maintain financial flexibility ahead of the 2021 offseason.
It's been a sensational rise for Athens native Antetokounmpo, a trajectory as steep as it was improbable. Despite toiling in near anonymity as a gangly teenager in the second tier of Greece's domestic league, the Bucks introduced Antetokounmpo, the son of Nigerian immigrants, to the broader basketball world by selecting him No. 15 overall in the 2013 draft.
As a rookie in 2013-14, Antetokounmpo averaged 6.8 points, 4.4 rebounds, and 1.9 assists in just under 25 minutes per game, mostly coming off the bench for a 15-win Bucks team. His 46.3% effective field-goal rate indicated he wouldn't be a major concern for opposing defenses.
However, Antetokounmpo showed improvement on both ends of the floor in every season since his debut, growing into a 6-foot-11 frame with a 7-foot-3 wingspan.
By 2016-17, his fourth year in the league, Antetokounmpo had improved his per-game averages to 22.9 points, 8.8 rebounds, 5.4 assists, 1.9 blocks, and 1.6 steals per game. He made his first of four straight All-Star appearances that season and capped off the campaign by being named the league's Most Improved Player.
In 2019-20, he averaged career highs in points (29.5) and rebounds (13.6) while adding 5.6 assists, one block, and one steal per outing. His 58.9% effective field-goal clip placed him in the 71st percentile among all big men, according to Cleaning the Glass.
Antetokounmpo's impact on the Bucks franchise has been profound. In the seven years prior to his arrival in 2013, the team posted just one winning record (2009-10); in the seven seasons since, Milwaukee has qualified for the playoffs five times and hasn't fallen short of the postseason since 2016.
The Bucks have advanced as far as Game 6 of the 2019 Eastern Conference finals with Antetokounmpo leading the charge. With a reconfigured roster of high-caliber supporting players, including two-way guard Jrue Holiday and holdover All-Star Khris Middleton, Milwaukee enters the 2020-21 season as one of the favorites to advance to the 2021 NBA Finals.
In addition to his two MVPs, Antetokounmpo earned his first career Defensive Player of the Year honor this past season.
Antetokounmpo's extension is the largest contract in NBA history.