Isabel Castaño Restrepo was born in Marulanda, Caldas, Colombia, on 11 January 1906, as the 6th of 13 children born to parents Segundo Castaño Jaramillo and Dolores Restrepo Morales.

At the age of 41, she married Jesús Antonio Lugo in Manizales, Colombia. The couple had two children, one of them being Danilo (born in 1949). The couple created a cosmetics company.

After the kidnapping and disappearance of her husband in Colombia, she emigrated to Venezuela in 1973. She later moved to the United States and lived in Washington, New Jersey, and New York before moving to Miami Beach, Florida (where she has lived for 20 years). At the time of her 110th birthday, she resided at the Ponce Plaza Nursing Center.

Isabel Castaño Restrepo died in Miami Beach, Florida, USA on 6 February 2018 at the age of 112.