"We are honored to have Giannis join our team of Milwaukee Brewers investors," Brewers principal owner Mark Attanasio said in a statement. "Giannis is a great athlete, a world champion, and a true local hero with international renown."
Antetokounmpo is following in the footsteps of Kansas City Chiefs star quarterback Patrick Mahomes, another star athlete in a small market investing in local teams. Mahomes joined the Kansas City Royals' ownership group last year, then bought a stake in MLS franchise Sporting Kansas City earlier this year.
The 26-year-old Antetokounmpo becomes the first individual investor to join the Brewers' ownership group since Attanasio bought the team in 2005.
"The city of Milwaukee means so much to me," Antetokounmpo said in a news release. "I am honored to be joining the Brewers ownership group to further my commitment and dedication to this great community. I take great pride in my city and I'm excited about what we can build together."
Antetokounmpo's decision to buy a stake in the Brewers comes one month after he guided the Bucks to their first NBA championship in 50 years.
Antetokounmpo cemented his commitment to the Bucks organization and the city of Milwaukee when the two-time NBA MVP signed a five-year, $228 million supermax extension with the franchise in December.
Entering Friday, the first-place Brewers held an 8 1/2-game lead in the National League Central. The club has won four of its last five games.