Grandson Rogelio Marrero confirmed the death Wednesday afternoon.
Marrero was a diminutive right-hander from Cuba who went by the nickname "Connie" when he pitched for the Washington Senators in the 1950s.
He was renowned for his control and for his presence on the mound despite standing just 5 feet 5 inches tall and weighing 158 pounds.
Marrero was born April 25, 1911, in the town of Sagua la Grande, about 220 miles (350 kilometers) east of Havana.
He became the oldest living ex-Major Leaguer in February 2011 after the death of former Brooklyn Dodgers infielder Tony Malinosky.