The move is reported to be worth around €4.5m plus bonuses and marks the third piece of outside recruitment sporting director Markus Krösche has made this summer, following the arrivals of Noel Aséko from Bayern Munich and Malik Pimpong from FC Midtjylland.
Standing 1.93m tall, Otávio will wear the number five shirt in Frankfurt and travels to the club's training camp in Grassau after completing his medical, having left Brazil in 2024 from the youth ranks of Botafogo and Camboriú before joining Estrela's Under-23 side. His rise since then has been rapid: he made his senior breakthrough within weeks of arriving in Portugal and went on to make 22 Liga Portugal appearances last season, 17 of them as a starter, helping the club retain its top-flight status.
"With Otávio, we're bringing in a young, highly talented centre-back with a lot of potential for development," said sporting director Timmo Hardung.
"He's a left-footer who is tall, athletic and quick, combining those attributes with a strong defensive mentality, which is something we specifically wanted to strengthen in our squad.
"We're convinced he'll bring us a lot of joy here at Eintracht."
Otávio himself struck a similarly excited tone on completing the move: "I am very happy to wear the Eintracht Frankfurt jersey. Joining a club with such a rich tradition that competes in major tournaments is a dream come true and a very important step in my career."