Official celebrations are planned for the central Umayyad Square in Damascus, which has already been packed with jubilant gatherings ahead of December 8, and elsewhere around the country.
Assad fled Syria for Russia a year ago as rebels commanded by Syria's new president, Ahmed al-Sharaa, seized Damascus, toppling him more than 13 years into the war that spiralled out of an uprising against his rule.
Celebrations have been underway in some parts of Syria for several days: thousands of people filled the streets of Hama on Friday, waving Syria's new flag as they marked the day insurgents led by Sharaa's Islamist Hayat Tahrir al-Sham group captured the city during their rapid march to Damascus.
The Kurdish-led administration that runs the northeast has congratulated Syrians on the anniversary but banned gatherings or events on security grounds, citing increased activity by "terror cells" seeking to exploit the occasion.
In a speech in late November marking the first anniversary of the start of the rebels' victorious campaign, Sharaa - a former al Qaeda commander - urged all Syrians to rally in the squares to show their joy and demonstrate national unity.
Sharaa has ushered in big changes, reshaping Syria's foreign ties as he forged relations with the United States and won support from Gulf Arab states, while turning away from Assad's backers Iran and Russia. Crippling Western sanctions have largely been lifted.
Sharaa has promised to replace Assad's brutal police state with an inclusive and just order.
But hundreds of people have been killed in bouts of sectarian violence, causing new displacements and fuelling mistrust among minorities towards Sharaa's government as he struggles to bring all Syria back under Damascus' authority.
The Kurdish-led administration has sought to safeguard its regional autonomy, while in the south, some Druze - followers of a minority sect that is an offshoot of Islam - are demanding independence.
Sharaa told attendees at a forum in Qatar over the weekend that "Syria today is living its best times," despite the bouts of violence that have taken place, promising accountability for those responsible.
He said a transitional period led by him would continue for four more years, to set up institutions, laws and a new constitution - to be put to a public vote - at which point the country would hold elections.
The Assad family, members of Syria's Alawite minority community, ruled Syria for 54 years.
The Syrian war killed hundreds of thousands of people and displaced millions more since 2011, driving some 5 million into neighbouring countries as refugees.
The central bank governor, speaking at a Reuters NEXT conference last week, said the return of some 1.5 million refugees was helping the economy grow.
The UN Office for the Coordination of Humanitarian Affairs says humanitarian needs across Syria are acute, with some 16.5 million people needing aid in 2025.
