The Comisión Nacional del Mercado de Valores (CNMV) announced on Tuesday Botín died of a heart attack.
Born in 1934 in the northern Spanish city of Santander, Botín came from a long line of bankers. His father and his uncle were both Chairmen of Santander Bank.
He began working for Santander in 1958 and within six years he was named director general.
Botín is survived by his wife, Paloma O'Shea Artiñano, and six children.