"He will continue his role in civil society in Syria," he said.
Kilo, who was arrested in May 2006 along with seven other opposition activists, was sentenced to three years in prison on charges of "weakening national sentiment" and "undermining the image of the state."
Prior to his arrest, he had signed the Beirut-Damascus Declaration, a petition urging Syrian recognition of Lebanon's independence.
The document, which was signed by 274 Syrian and Lebanese intellectuals, also called for the the two neighbours to forge diplomatic relations.
Anwar al-Bunni, another signatory to the declaration, had received a five-year sentence on the same charge as Kilo, and is still in jail.
Kilo's arrest was widely criticised by Lebanese and Syrian political groups opposed to Damascus' policy on Lebanon.
The US and the European Union had also called on the Syrian government to free Kilo.
Lamis Andoni, Al Jazeera's senior political analyst, said Kilo's release comes amid US efforts to engage in constructive dialogue with Damascus.
"[Kilo's release] is partly a result of international pressure but it also shows that Damascus is responding to the policy of engagement that Obama has initiated since he has become president," she said.
"Kilo is widely respected in the Arab world and the allegations that he was serving Washington's interests, as the conviction implied, had little credibility."
Syria and Lebanon formally established diplomatic relations in October, more than 60 years since they each won independence from France.
That came nearly three-and-a-half years after Syrian troops and security officials pulled out of Lebanon after a 29-year presence, in the wake of public anger over the assassination of Rafiq al-Hariri, a former Lebanese prime minister.
Critics of Damascus alleged that Syrian agents and pro-Syrian Lebanese officials had organised the killing, claims that the Syrian authorities have repeatedly denied.
Syria's political system has been run by the Baath Party since it took power in a 1963 coup. The party swiftly moved to ban all opposition to its rule.