Timothy Donald Cook (born November 1, 1960) is an American business executive who served as the chief executive officer (CEO) of Apple Inc. from 2011 to 2026, and has been the company's executive chairman since September 2026. Cook joined the technology company in 1998 as senior vice president for worldwide operations, and later served as vice president for worldwide sales and operations and then as chief operating officer under co-founder Steve Jobs. He was appointed chief executive in 2011, when Jobs resigned due to failing health. Under Cook, Apple grew into one of the world's most valuable companies; in 2025 it was the second largest technology company by revenue in the world, at US$416 billion. Cook led a succession plan that saw John Ternus succeed him as CEO.