Traffic was congested as thousands flocked to the Hezbollah bastion, a densely-packed residential area that had largely been emptied out as Israel launched near-daily strikes in recent weeks.
Some broke into tears as they saw what remained of their destroyed homes and businesses, AFP journalists reported, while others waited for excavators to remove the rubble from their streets to access their buildings.
"We are returning to these heroic suburbs, the suburb of (slain Hezbollah leader) Sayyed Hassan Nasrallah... We returned thanks to them," engineer Nizam Hamade told AFP as he headed back towards his home.
"The resistance is victorious," he said referring to Hezbollah.
On Tuesday, the south Beirut suburb -- known as Dahiyeh in Arabic -- saw the most intense strikes of the conflict.
"We headed back home at 04:00 (02:00 GMT) just as the ceasefire came into place," resident Fatima told AFP, giving only her first name.
As a truce came into effect Wednesday morning, the Iran-backed group was organising press tours in south Beirut, as well as its south and east Lebanon strongholds.
After nearly a year of limited cross-border fire initiated by Hezbollah over the Gaza war, Israel ramped up its aerial bombing of Lebanon on September 23, mainly hitting Hezbollah strongholds. It later sent ground troops across the southern border.
On September 27, a massive Israeli air strike killed Hezbollah's charismatic leader Nasrallah in south Beirut.
Some residents told AFP they immediately headed towards the place where their beloved leader, who has not had a funeral procession or public burial amid the war, was killed.
"I was looking for the place where we lost our souls," Diala told AFP, referring to the site of that deadly strike.
"I headed straight there and didn't look at anything else."
Hezbollah supporters were handing out pictures of Nasrallah and Hashem Safieddine, who was widely expected to be named his successor before he was killed in a strike in early October.
Early Wednesday, an AFP journalist heard celebratory gunfire as Hezbollah supporters on scooters brandished the group's yellow flag.
One man waved Hezbollah's flag above the ruins of a building.
The war has killed more than 3,800 people in Lebanon since October 2023, according to the health ministry, most of them since September.
