While many mistakenly say that John F. Kennedy was the youngest president of the United States, this is in error. He was the youngest president ever elected to the presidency at the age of 43. However, Theodore Roosevelt was the youngest man to serve as president when he took over after William McKinley’s assassination. He was 42.
Here are the ages of the ten youngest presidents:
Theodore Roosevelt – 42 years, 322 days
John F. Kennedy – 43 years, 426 days
Bill Clinton – 46 years, 154 days
Ulysses Grant – 46 years, 236 days
Barack Obama – 47 years, 169 days
Grover Cleveland – 47 years, 351 days
Franklin Pierce – 48 years, 101 days
James Garfield – 49 years, 105 days
James K. Polk – 49 years, 122 days
Millard Fillmore – 50 years, 184 days
Agencies