Moqtada Al Sadr, the powerful Iraqi cleric, has been received by Saudi Arabia's Crown Prince Mohammed bin Salman in the latest meeting between senior Iraqi and Saudi figures.
The visit was his first in 11 years and comes after Iraq’s interior minister and prime minister held meetings in the kingdom in recent weeks.
Shortly after Mr Al Sadr's arrival in Jeddah on Sunday, he was met by the Saudi minister of state for Gulf affairs, Thamer Al Subhan.
"We have been very pleased with what we found to be a positive breakthrough in the Saudi-Iraqi relations, and we hope it is the beginning of the retreat of sectarian strife in the Arab-Islamic region," a statement from Mr Al Sadr's office said.
The Shiite cleric, who comes from a powerful line of religious figures, commands huge support in Iraq, leading vast protests against government.
His Saudi visit is the latest sign of an improvement in relations between the two countries, which have a trouble tempestuous past.
Despite their troubles, Saudi Arabia has always expressed its support for the Iraqi government in its efforts to fight terrorism.
Mr Al Sadr’s visit comes less than two weeks after interior minister Qasim Al Araji met with Saudi Arabia's Crown Prince Mohammed bin.
Prime minister Haider Al Abadi also visited the kingdom last month to improve relations.
Earlier in the year, Saudi foreign minister Adel Al Jubeir headed to Baghdad for talks with Mr Al Abadi, the first such visit since 2003.
Despite the visits, Saudi Arabia is concerned about Iran’s influence in Iraq, particularly through the Shiite paramilitary force, known as the Hashed Al Shaabi, which has played a major role in fighting ISIL.