© Getty Images

Joe Biden -

Joe Biden took office in 2021, at the age of 78: making him the oldest president in US history.

© Getty Images

Donald Trump -

Donald Trump was 70 years old at the time of his presidential inauguration, making him the second-oldest US president to take office.

© Getty Images

Ronald Reagan -

Ronald Reagan was sworn in as president at age 69, and ended his presidency at the age of 77. He remains one of the oldest US presidents in history.

© Getty Images

William Henry Harrison -

William Henry Harrison died just 31 days after being sworn in as the ninth president of the United States. Harrison was 68.

© Getty Images

James Buchanan -

James Buchanan was 65 when he took office as the 15th president of the United States, in 1857.

© Getty Images

George H. W. Bush -

George H. W. Bush served as the 41st US president from 1989 to 1993. Bush was 64 at the time of his inauguration.

© Getty Images

Zachary Taylor -

The American military leader began his term as the country's 12th president in 1849, at the age of 64.

© Getty Images

Dwight D. Eisenhower -

Eisenhower was sworn in as the 34th president of the United States in 1953. He was 62.

© Getty Images

Andrew Jackson -

Andrew Jackson became the seventh president of the United States in 1829, aged 61.

© Getty Images

John Adams -

The former leader of the American Revolution became the nation's second president in 1797. John Adams was 61 at the time.

© Getty Images

Gerald Ford -

Gerald Ford served as the 38th US president, from 1974 to 1977. He was 61 at the time of his inauguration.

© Getty Images

Harry Truman -

President Truman took office in 1945, at the age of 60.

© Getty Images

James Monroe -

The Founding Father served as the fifth US president, from 1817 to 1825. Monroe was 58 at the time of his inauguration.

© Getty Images

James Madison -

The "Father of the Constitution" was 57 when he was sworn in as the fourth president of the United States, in 1809.

© Getty Images

Thomas Jefferson -

The Founding Father behind the Declaration of Independence was 57 when he became president.

© Getty Images

John Quincy Adams -

The former US secretary of state served as the nation's sixth president from 1825 to 1829. Adams took office at the age of 57.

© Getty Images

George Washington -

The American Founding Father became the first president of the United States in 1789. George Washington took office at the age of 57.

© Getty Images

Andrew Johnson -

Andrew Johnson was 57 at the time of his inauguration as the 17th president of the United States, in 1865.

© Getty Images

Woodrow Wilson -

The former president of Princeton University and governor of New Jersey was sworn in as the 28th president of the United States in 1913, at the age of 56.

© Getty Images

Richard Nixon -

Richard Nixon took office as the 37th president of the United States in 1969. He was 56 years old.

© Getty Images

Benjamin Harrison -

Benjamin Harrison was sworn in as the 23rd president of the United States in 1889, and served until 1893. He was 55.

© Getty Images

Warren G. Harding -

Warren G. Harding served from 1921 until his death in 1923. Harding took office at the age of 55.

© Getty Images

Lyndon B. Johnson -

LBJ took office in 1963, following the assassination of John F. Kennedy. The 36th president of the United States was 55.

© Getty Images

Herbert Hoover -

Herbert Hoover became president in the year the Great Depression hit the country—1929. He was 54 at the time.

© Getty Images

George W. Bush -

George W. Bush served as the 43rd US president from 2001 to 2009. Bush was also 54 when he took office.

© Getty Images

Rutherford B. Hayes -

Rutherford B. Hayes was also 54 years old when he was sworn in as the nation's 19th president.

© Getty Images

Martin Van Buren -

The eighth president of the United States was 54 when he took office.

© Getty Images

William McKinley -

William McKinley was in office from 1897 until his assassination in 1901. He was 54 at the time of his inauguration.

© Getty Images

Jimmy Carter -

The 39th president of the United States served from 1977 to 1981. Jimmy Carter was 52 when he took office.

© Getty Images

Abraham Lincoln -

The president who issued the Emancipation Proclamation was 52 at the time of his inauguration in 1861.

© Getty Images

Chester A. Arthur -

Chester A. Arthur began his presidential term in 1881, at the age of 51.

© Getty Images

William Howard Taft -

William Howard Taft was the only person to serve as both chief justice and president of the United States. He was sworn in as president at the age of 51.

© Getty Images

Franklin D. Roosevelt -

FDR was elected president four times, making him the only US president to have served more than two terms. Roosevelt was 51 at the time of his first inauguration in 1933.

© Getty Images

Calvin Coolidge -

The 30th president of the United States took office at the age of 51.

© Getty Images

John Tyler -

John Tyler served from 1841 to 1845. He was 51 at the time of his presidential inauguration.

© Getty Images

Millard Fillmore -

Millard Fillmore took office after President Zachary Taylor died in 1850. Fillmore was 50 at the time. 

© Getty Images

James Polk -

The former speaker of the House of Representatives and governor of Tennessee served as the 11th US president from 1845 to 1849. He was 49 when he landed the top job.

© Getty Images

James Garfield -

James Garfield had been in office for just 200 days when he was assassinated in 1881. Garfield was 49 when he became president.

© Getty Images

Franklin Pierce -

Franklin Pierce served as president from 1853 to 1857. Pierce was 48 when he took office.

© Getty Images

Grover Cleveland -

Grover Cleveland holds a special place in American history; he's the only presidential candidate to win the office, lose the presidency in an election, and then come back to become president again. Cleveland was 47 during his first inauguration in 1885.

© Getty Images

Barack Obama -

Barack Obama not only made history by becoming the first African-American US president, but he's also one of the youngest to take office. Obama was 47 at the time of his inauguration.

© Getty Images

Ulysses S. Grant -

Ulysses S. Grant was elected president in 1868 and took office the following year at the age of 46. Grant made history at the time, becoming the youngest president up to that date.

© Getty Images

Bill Clinton -

After being governor of Arkansas for 12 years, Bill Clinton became  the 42nd US president at the age of 46.

© Getty Images

John F. Kennedy -

JFK was just 43 when he took office as president of the United States in 1961. President Kennedy's tenure abruptly came to an end with his assassination in 1963. Although Roosevelt is the youngest president, John F. Kennedy is the youngest elected president in US history.

© Getty Images

Theodore Roosevelt -

Teddy Roosevelt is the youngest US president in history, at the age of 42. Roosevelt became president in 1901, after William McKinley was assassinated.

Sources: (U.S. News & World Report) (Pew Research Center) (Deseret News)

See also: US presidents who didn't serve a second term

© Getty Images