The 6-foot-1 point guard, who committed to the Hoosiers in February, was the top-rated player at his position and ranked 12th overall on the ESPN 60 for 2021.
"I knew when I first saw Khristian at 15 years old, that he was a special player," head coach Archie Miller said in a statement. "He has great feel for the point guard position.
"His competitive drive has pushed him to elevate his game rapidly and his family has done a great job of keeping him grounded and humble."
Lander joins incoming four-star prospects Jordan Geronimo and Trey Galloway.
Indiana went 20-12 overall this past season, but the Hoosiers finished a disappointing 9-11 in Big Ten play. However, all five starters are returning to Bloomington, including All-Big Ten third-team selection Trayce Jackson-Davis.