There have been a number of international sanctions against Iran imposed by a number of countries, especially the United States, and international entities. Iran was the most sanctioned country in the world until it was surpassed by Russia after Russia's 2022 invasion of Ukraine.
The first sanctions were imposed by the United States in November 1979, after a group of radical students seized the American Embassy in Tehran and took hostages. These sanctions were lifted in January 1981 after the hostages were released, but they were reimposed by the United States in 1987 in response to Iran's actions from 1981 to 1987 against the U.S. and vessels of other countries in the Persian Gulf and Iranian support for terrorism.