Here’s a look at the top 10 oldest United States Presidents to take the oath.

The oldest? You may have guessed it, Ronald Regan.

He took the office in 1981 at 69 years old.

Theodore Roosevelt is the youngest.

He took the office in 1901 at the age of 42.

Find the complete list of top 10 oldest United States presidents below:

  1. Ronald Reagan: 69 years old
  2. William Henry Harrison:68 years old
  3. James Buchanan: 65 years old
  4. George H.W. Bush: 64 years old
  5. Zachary Taylor: 64 years old
  6. Dwight D. Eisenhower: 62 years old
  7. Andrew Jackson: 61 years old
  8. John Adams: 61 years old
  9. Gerald Ford: 61 years old
  10. Harry Truman: 60 years old