The visit is seen as the latest move by the EU to save the 2015 nuclear deal between Tehran and world powers.
Tensions between Iran and the U.S. have steadily risen since President Donald Trump withdrew from the nuclear agreement and re-imposed sanctions on Iran in 2018. Tehran has responded by gradually rolling back its commitment to the deal.
Josep Borrell will meet with Iranian Foreign Minister Mohammad Javad Zarif and other Iranian officials on Monday, according to IRNA.
The visit to Tehran is Borrell's first since taking office. Borell met the Iranian foreign minister in Brussels in January, when European foreign ministers organized a special meeting to discuss the ongoing crisis.
After the U.S. drone attack that killed Iran's top general Qassim Soleimani in January, Iran announced that it would no longer respect limits set on how many centrifuges it can use to enrich uranium.
Zarif said the move was a "remedial step" taken within the framework of the nuclear deal. He said it could be reversed.
The deal struck in 2015 aims at capping Tehran's nuclear activities in return for lifting sanctions. Iran signed the accord with the United States, France, Germany, the United Kingdom, Russia and China.