Syrian President Bashar Assad. AP
The host of Friday's summit, Saudi Arabia, has championed Assad's return to the pan-Arab body and invited the Syrian leader over the objection of other regional leaders.
The Syrian government had been isolated in the region for years since its crackdown on protests in 2011 triggered a war that has killed more than 500,000 people.
Analysts say Assad's invitation also shows the clout of Saudi Arabia, which is casting itself as a peacemaker and asserting itself in multiple crises across the Middle East.
Following a preparatory meeting on Wednesday, Syrian Foreign Minister Faisal Mekdad told reporters Assad would attend Friday's event in Jeddah in person.
Beyond rekindling ties with the Assad government, the summit is expected to devote energy to two conflicts: the month-old showdown between two generals in Sudan and the eight-year-old civil war in Yemen.
It is taking place in the same city where representatives of the two Sudanese camps have been locked in negotiations for a week and a half brokered by Saudi and US officials.
In Yemen, meanwhile, Saudi Arabia is pushing for a peace deal with Iran-backed Houthi rebels after eight years at the helm of a military coalition that failed to defeat them on the battlefield.
Neither initiative has yielded a major breakthrough so far, but Saudi op-ed writers and analysts are bullish.
"The Jeddah summit is one of the most important summits for a long time because it will rebuild the Arab region in a way that relies on shared interests and turns challenges into opportunities," said Saudi political commentator Suleiman al-Aqili.
"If the summit is able to reintegrate Syria into the Arab system and take a strong position on the conflict in Sudan and Yemen, it will be successful."
Wave of reconciliation
Recent diplomatic shifts were accelerated by a surprise Chinese-brokered normalisation deal with Iran announced on March 10.
Less than two weeks later, Saudi Arabia announced it had begun talks on resuming consular services with Iran ally Syria, the first public step in a rapprochement that has since seen the countries' foreign ministers exchange visits.
Yet Assad's presence in Jeddah on Friday does not guarantee progress on resolving Syria's brutal war.
In areas of northwestern Syria that remain under rebel control, there have been repeated mass protests against Assad's return to the Arab fold.
Nor is it clear that the pan-Arab body can extract concessions on issues like the fate of Syrian refugees or the surging captagon trade.
"It's important to remember that Assad's return to the Arab League is a symbolic measure to begin the process of ending his regional isolation," said Anna Jacobs, senior Gulf analyst with the International Crisis Group.
"In many ways it is the start of political normalisation, but it will be even more important to watch if economic normalisation comes with it, especially from Gulf Arab states."
Assad's stay in Jeddah will be followed across the region, perhaps nowhere more closely than in Damascus.
"This is the first time in many years that my family and I have been interested in political news because we had lost hope," said Haidar Hamdan, a 44-year-old geography teacher in the Syrian capital.
His country's reintegration into the Arab League represents a "return to the world order", he said, adding that he expected shuttered embassies and companies to reopen and "movement and life (to) return to the country".
Other Damascus residents have more subdued expectations.
"We are optimistic, but we know that the Arab summit is not a magic wand that can be waved to solve all of Syria's problems," said Sawsan, a 29-year-old who works at a car dealership.