- The move is further evidence of a thaw in relations between Damascus and other Arab governments.
- It comes ahead of a summit in Saudi Arabia later this month that President Bashar al-Assad may now attend.
Image: EPA
Syria is back in the influential Arab League, more than a decade after being thrown out for its brutal repression of pro-democracy protests, which led to the ongoing civil war.
The move is further evidence of a thaw in relations between Damascus and other Arab governments.
Syria's readmittance was approved at a meeting of League members in Egypt.
It comes ahead of a summit in Saudi Arabia later this month that President Bashar al-Assad may now attend.
In a statement, Syria's foreign ministry said it had received the League's decision "with great attention" and called for "greater Arab cooperation and partnership".
Foreign ministers from 13 of the 22-nation group's members were present when the decision to readmit Syria was taken.
They stressed the need to end Syria's civil war and the resulting refugee and drug smuggling crises. Growing poverty and lack of job opportunities saw many turn to the drug trade, the BBC reported last year.
A committee involving Egypt, Saudi Arabia, Lebanon, Jordan and Iraq will be set up to help Syria achieve those goals.
The Arab League's secretary general, Ahmed Aboul Gheit, said the move was the start of a process to resolve the crisis in Syria, which would be "gradual".
He stressed the decision did not mean a resumption of relationships between Arab states and Syria as it was up to each country to decide this individually.
More than 300,000 civilians are thought to have been killed and more than 100,000 detained or disappeared during the civil war, according to UN estimates.
Roughly half of the pre-war population of 21 million has been displaced, either within Syria or as refugees abroad.
Mr Assad began to regain control over the country in 2015, with the help of Russia - forcing its neighbours to think of a future with Mr Assad in place.
Arab moves to restore ties accelerated after the devastating earthquake that hit Turkey and Syria in February.
Earlier this week, Iranian President Ebrahim Raisi visited Mr Assad - with some analysts suggesting the visit put extra pressure on Arab nations to bring Syria back into the fold.
It follows visits by foreign ministers from Egypt and Saudi Arabia and the restoration of full diplomatic relations with Tunisia.
Syria's foreign minister has also recently visited several Arab countries as part of a diplomatic push.
The US and UK are among the Western countries that have recently stated they will not restore relations with President Assad's government.