STORY: A ceremony was held inside the embassy's compound with dozens of diplomats and officials attending the reopening of the diplomatic mission.
In March, Iran and Saudi Arabia agreed, in a deal brokered by China, to end a diplomatic rift and re-establish relations following years of hostility that had endangered regional stability including in Yemen, Syria and Lebanon. The deal also highlighted China's growing influence in the Middle East.
Sunni Saudi Arabia severed relations with Shi'ite Iran following the storming of its embassy in Tehran in 2016 after a dispute over the execution of a Shi'ite Muslim cleric.
The relationship had begun worsening a year earlier, after Saudi Arabia and the United Arab Emirates intervened in Yemen's war, where the Iran-aligned Houthi movement had ousted a Saudi-backed government and taken over the capital Sanaa.
The kingdom also has blamed the Islamic Republic for missile and drone attacks on its oil facilities in 2019 as well as attacks on tankers in Gulf waters. Iran denied the charges.