Adonis Ratliff is a 6-11 power forward from Archbishop Stepinac in White Plains, New York, and the son of 16-year NBA veteran and 2001 All-Star Theo Ratliff. He and his identical twin brother Darius both committed to USC as a package deal on October 22, 2025, drawn by coach Eric Musselman's NBA-style development system — Musselman previously coached their father as an assistant with the Atlanta Hawks. At Stepinac, Adonis averaged 12.3 points, 8.7 rebounds, and 3.5 blocks as a junior, and was selected as a McDonald's All-American alongside his twin and teammate Jasiah Jervis, giving Stepinac three players on the 2026 roster. He plays for the PSA Cardinals and is regarded as the more offensively polished of the twins, with a soft touch extending to the three-point line.