List of presidents of the United States by age
The median age upon accession to the presidency is 55 years and 3 months. This is how old Lyndon B. Johnson was at the time of his inauguration. The youngest person to assume the office was Theodore Roosevelt, who became president at the age of , following William McKinley's assassination; the oldest was Donald Trump, who was old at his inauguration. The youngest person to be elected president was John F. Kennedy, at of age on election day; the oldest was Ronald Reagan, who was old at the time of his election to a second term.
Baby of the House
In the 116th Congress, which began on 3 January 2019, the youngest member of the United States House of Representatives is Alexandria Ocasio-Cortez, who was born on , and was first elected in 2018. She is also the youngest woman elected to the House in U.S. history.