Bernadette Hernandez suffered a brain aneurysm, according to a publicist for Mars' label, Atlantic Records. She died Saturday at Honolulu's Queens Medical Center.
Hernandez came to the U.S. from the Philippines and nurtured her son's interest in music at an early age.
Mars is one of pop's top acts with several No. 1 hits including his most recent, "When I Was Your Man." He is also known for hits like "Just The Way You Are" and "The Lazy Song."
The Associated Press contributed to this report.