She was 87.
She was part of a trilogy of the most famous Cuban singing divas - the others were Celia Cruz and La Lupe.
Guillot was the last survivor. Her biggest hit was "Mienteme" (Lie to Me).
Exiles affectionately called her "Olgita de Cuba." A native of Santiago de Cuba, Guillot and her family moved to Havana when she was a small child. As a teenager, she and her sister, Ana Luisa, performed as the Duo Hermanitas Guillot.
In 1945, her talent as a singer of slow, romantic songs was discovered by Facundo Rivero, an influential man in the Cuban music industry of the era.
In 1954, she recorded "Mienteme", which became a hit across Latin America and earned her three consecutive awards in Cuba as her homeland's best female singer.
She is survived by her daughter, Olgita.