People.com said Marie's brother Donny gave a moving eulogy at the service, which took place at the Church of Jesus Christ of Latter-day Saints Chapel in Provo.
A slide show of the teen in happier times played in the lobby of the chapel and Thomas S. Monson, the president of the Church of Jesus Christ of Latter-day Saints, officiated the funeral service, People.com said.
Michael reportedly suffered from depression and leaped to his death from the eighth floor of his Los Angeles apartment building late last month.
Sibling entertainers Donny and Marie Osmond took a break from performing their Las Vegas stage show to grieve for Michael. They are expected to resume performing Tuesday.