The oil industry is one of the most effective and largest industries in the world, especially in Iran. The nationalization of Iran's oil industry is one of the most important historical events in political life, during which Iranians entered the political arena to not only burn the roots of foreign colonization forever, but also to pave the way for the country's development. The present article deals with the role of the clergy in the nationalization of the oil industry; It is an important and remarkable event, which should be considered as one of the important experiences. It can be concluded that the nationalization of the oil industry of our beloved country Iran, which cut off foreign aid from looting and plunder of this national capital, what played a key role in this regard, and it can be considered as the center of gravity of this He considered the victory to be sweet and great, the close and strong connection of the masses with the clergy, especially Ayatollah Kashani (may God have mercy on him), who awakened the nation with his enlightenment and woke them from their slumber, and this caused It became possible that even the properties of the society, such as Dr. Mossadegh, had the opportunity to grow and be able to stand against the court and the British with the blessing of this strong support and nationalize the oil industry; Also, the open political space after Shahrivar 1320 provided the field of activity for all classes, including the clergy. In the aftermath, the clergy also regained their lost power and took a stand against various currents, including the nationalization of the oil industry, in order to nationalize Iran's oil industry.