20. Barack Obama (IQ 145-150)
While former President Barack Obama’s IQ was never formally tested, it’s believed to be around 145-150, which is well above average. Based on how well Obama ran the country from 2008-2016, he is considered one of the smartest presidents to grace the Oval Office.
19. James Polk (IQ 143.4)
A member of the Democratic Party, former President James Polk is considered one of the last strong presidents before the Civil War. With an IQ of 143.4, Polk was the 11th president of the United States and best known for his territorial expansion of the U.S. through the Mexican-American War.
18. George H.W. Bush (IQ 143)
President George H.W. Bush has an IQ of 143 and is the oldest living former president at the age of 91. During his presidency, he passed the Americans with Disabilities Act and led a grand coalition with Arab nations, finally creating trust between those countries and the United States.
17. Richard Nixon (IQ 142.6)
You would think with such a high IQ, former President Nixon wouldn’t have made some of the decisions that led to the Watergate Scandal. He is the only president in the history of the United States to resign, and was succeeded by Gerald Ford.