JoAnn Bus was married to former Lakers owner Jerry Buss.
The Buss family has requested people to donate to the American Cancer Society or the Lakers Youth Foundation in lieu of sending flowers.
"I was saddened to hear the news that JoAnn Buss, mother of Jeanie, Johnny, Jim and Janie, and wife of Dr. Buss, has passed away," Magic Johnson said on Twitter. "She was an incredible friend and woman. Cookie and I are glad she was a part of our lives for more than 40 years."
LeBron James also offered his condolences to the Buss family.
Jerry Buss and JoAnn divorced in 1972. Jerry Buss died in 2013.
City News Service contributed to this report.