"Antetokounmpo has informed [Flyer's head coach Anthony] Grant that he desires to pursue a professional basketball career, and will not return to school," said a statement from the University.
Dayton finished 14-17 this season, their worst record since the 2005-2006, and only the second time in the last 20 years they've failed to finish above .500.
Before the start of the season, six-year head coach Archie Miller left to coach the Indiana Hoosiers.
Currently, Antetokounmpo isn't featured on any prominent NBA draft boards, something that could change in the coming days given he wasn't expected to leave until next year at the earliest.
NBA teams could find intrigue in the 6'10, 190-pound forward who turned 20-years-old in December, but another option for the third of the five Antetokounmpo sibling would be to play overseas like his oldest brother, Thanasis. Thanasis currently plays in Greece for Panathinaikos after he spent some time with the New York Knicks during the 2015-2016 season.
Before college, Kostas played for suited up for Dominican High School in Whitefish Bay, Wisconsin and helped the program win five straight Division 4 titles.