Wes Leonard's shot capped his team's perfect season. Leonard fell to the ground after teammates and fans rushed the court.
A cause of death has not yet been determined.
The 16-year-old Fennville High junior was also the quarterback of the school's football team and was described by his coach as "the best player on the basketball team."
Earlier in the season, Leonard had eclipsed the 1,000-point mark for his high school career.
Fennville Superintendent Dirk Weeldreyer remembered Leonard as "the quintessential all-American kid."
"He had a great grin and was always cheerful. Younger kids throughout the community looked up to him and idolized him," Weeldreyer said. "Wes was strong and powerful. As the quarterback of our championship football team, he could throw a dart 40 yards down the field. He had the body of a linebacker, but brought the ball up the floor for our 20-0 basketball team."
Grief counselors were on hand at the high school on Friday, the Fennville School District said.
Leonard is the second Fennville athlete to die in 14 months.
Wrestler Nathaniel Hernandez, 14, died in January of last year after suffering a seizure at home following his participation in a high school wrestling match, The Holland Sentinel reported.
The Associated Press contributed to this story.
