Cole died Tuesday at a hospice in Boca Raton, Fla., after a short battle with cancer, her family said.
A Boston native, she was singing as the opening act for the Mills Brothers in New York's Club Zanzibar when she met singer-pianist Nat Cole. They were married in Harlem in 1948.
"I was very involved in his life," she told the Boston Globe in 1989. "I dealt with his agent. I kept his books. I was there for all the wonderful moments of his life, the accolades. We shared everything. I merged into his life."
The Coles, whose purchase of a mansion in the exclusive, all-white Hancock Park neighborhood of Los Angeles in 1948 spurred a homeowners protest, traveled throughout Europe together in the 1950s — a time in which Maria resumed her singing career and recorded several songs with her husband for Capitol Records.
Nat Cole, whose hit songs included "Unforgettable"and "Mona Lisa" and whose 1956-57 TV musical-variety series "The Nat 'King' Cole Show" was the first network TV program hosted by an African American, died of lung cancer in 1965.
After his death, Maria Cole established the Cole Cancer Foundation and again returned to her singing career, beginning with a trial run at the Flamingo Hotel in Las Vegas in late 1966 and followed by an appearance on "The Ed Sullivan Show."
She also began co-hosting a live afternoon conversation-variety show with Stan Bohrman on KHJ-TV (Channel 9) in Los Angeles in 1967. Two years later, she married television writer and producer Gary Devore. They were divorced in 1978.
In 1990, Cole and her daughter Natalie accepted a Grammy lifetime achievement award for her late husband.
"I miss the closeness of my marriage to Nat," Cole said in the 1989 Boston Globe interview. "I loved hearing his key in the door. I loved preparing his meals. I loved being married to him."
The daughter of a postal worker, she was born Maria Hawkins on Aug. 1, 1922. She was 2 when her mother died in childbirth and her father was left to care for his three young daughters.
Cole, who took voice and piano lessons while growing up, was educated at the Palmer Memorial Institute, a prestigious African American prep school founded by her aunt in Sedalia, N.C.
After graduating in 1938, she attended a clerical college in Boston and began singing with a jazz orchestra at night. She soon moved to New York City and began singing with jazz great Benny Carter's band.
In 1943, she married Spurgeon Ellington, one of the Tuskegee Airmen, who was killed during a routine training flight shortly after the end of World War II.
She performed briefly with the Count Basie and Fletcher Henderson bands before becoming a vocalist for Ellington, with whom she stayed until 1946.
Cole, who lived in Ponte Vedra Beach, Fla., is survived by her three daughters, Natalie Cole, Timolin Cole-Augustus and Casey Cole-Hooker; her sister, Charlotte Hawkins; and six grandchildren.