The 19-year-old centre-back has penned a five-year contract with the Ligue 1 club, following Michy Batshuayi, Romain Alessandrini and Abdelaziz Barrada to the Stade Velodrome.
And the teenager was quick to express his joy at making the move to Provence.
"I'm very happy, honoured and proud to join Marseille," he told the club's official website.
"This is one of the biggest clubs in Europe, well known in Brazil.
"I am fully prepared and trained with Botafogo before I signed with Marseille. I'm in great shape, ready to play.
"I've heard of the passion fans of Marseille. I know they play a very important role. I saw pictures from the Stade Velodrome in the last game of Marseille against Nice, it was amazing."