Her publicist said the singer, who had been battling cancer, passed away this morning, surrounded by her family.
Summer was a five-time Grammy winner who first rose to fame in the 1970's with "Love to Love You Baby."
She followed with chart-topping hits like "Last Dance," "Bad Girls," "Hot Stuff" and "She Works Hard for the Money."
Her family issued a statement saying, they "are at peace celebrating her extraordinary life and her continued legacy."
Summer is survived by her husband, singer and producer Bruce Sudano, their two daughters and a third daughter from a previous marriage.