While terms of the deal weren't announced, sources tell ESPN that the transfer fee is $10 million, plus undisclosed incentives and a sell-on percentage.
Cincinnati said only that the deal was for a "club-record, multi-million-dollar transfer fee."
Brenner's former club Sao Paulo was due 20% of the net profit of any future transfer, but since Cincinnati is taking a loss on the original $13m transfer fee it paid Sao Paulo back in 2021, no additional fee from that aspect of the transfer will be paid back to the Brazilian club.
Sao Paulo will get a solidarity payment of at most $400,000 since Brenner came up through their youth system.
"We're extremely happy for Brenner that he's able to make this move and play in one of the biggest leagues in Europe," FC Cincinnati general manager Chris Albright said.
"Our ultimate goal at FC Cincinnati is to win games for our incredible fans, and we understand that developing players is central to attracting the best talent. This is a significant transfer for our club and is a testament to everything our staff has done in the past year and a half. Our ownership will continue to give us the resources to compete and this transfer only adds to that commitment."
The move sees Brenner's move to FCC pay off. He got off to a slow start in Cincinnati, scoring just eight goals in 33 league appearances during the 2021 campaign.
The 2022 season went much better, with the Brazilian scoring 18 goals in 31 league and playoff appearances as he formed a formidable partnership with Brandon Vazquez. Brenner has scored one goal so far this season, giving him a total of 27 goals along with eight assists in 71 appearances.
Brenner spent parts of four seasons as a professional with Sao Paulo, enjoying a breakout season in 2020 when he scored 22 goals in all competitions.