president that died the youngest
Trump supplants the previous oldest president, Ronald Reagan, who was 69 years, 11 months and 14 days old when he was first sworn in on January 20, 1981. John F. Kennedy is the youngest-ever elected president, aged 43. However, Theodore Roosevelt is the youngest person to ever become president. He was 42 when he succeeded to the presidency, following the assassination of William McKinley. The first table below summarises the most common questions asked about presidential ages.