What is Timeline of the governments in Iran and their reciprocal presidents in the United States?

This list shows the timeline of the governments in Iran along with their reciprocal presidents of the United States. See President of the Continental Congress for more information about all previous United States presidents. The list does not include the Acting president of the United States in accordance to the Twenty-fifth Amendment to the United States Constitution.

Naser al-Din Shah Qajar, the third longest reigning monarch in Iranian history, witnessed 14 US presidents during his reign, while Mohammad Ali Shah Qajar, the sixth shah of the Qajar Dynasty, coincided with only one US president.