Who is the youngest President of the United States?

• A. George Washington
• B. John F. Kennedy
• C. Ulysses S. Grant
• D. Theodore Roosevelt

Answer: (D)

Being the youngest to assume the presidency means the age at the moment someone first takes the oath of office. Theodore Roosevelt holds that distinction because he became president in 1901 after William McKinley’s assassination, at about 42 years old. That makes him younger than any other person who has begun serving as president.

George Washington was about 57 when he started, so he’s much older at the outset. John F. Kennedy was the youngest elected president at 43, but he was older than Roosevelt when sworn in. Ulysses S. Grant was 46 at inauguration, also older than Roosevelt.

So, the best answer is Theodore Roosevelt, the youngest to begin the presidency.