Who served as CEO of IBM for 42 years from 1914 to 1956?

Thomas J. Watson served as IBM’s chief executive from 1914 to 1956.

Watson joined the Computing-Tabulating-Recording Company (CTR) as general manager in 1914 and became its president in 1915. In 1924, he renamed CTR International Business Machines, giving IBM the identity it still uses today. His tenure lasted roughly 42 years and transformed a collection of office-machine businesses into a major international company.

Watson emphasized salesmanship, employee training, corporate discipline and the slogan “THINK,” helping create IBM’s distinctive management culture. Under his leadership, IBM became dominant in punched-card data-processing equipment before the computer era fully emerged.

A common mix-up is his son, Thomas J. Watson Jr., who succeeded him as IBM’s chief executive in 1956 and later guided the company into electronic computers and mainframes. Frank Cary and John Opel were also later IBM CEOs, not Watson’s predecessor or successor during the period named in the question.