"Our army units have gained full control of the Aleppo- Khanasser-Ithriya-Al-Salmiyeh road after eliminating a number of Daesh (IS) terrorists and it will be open for citizens from tomorrow morning," state television said.
The Syrian Observatory for Human Rights confirmed the road had been recaptured by the army, 12 days after IS forces severed it, placing the government-held sector of Aleppo under effective siege.
The city has been divided between government control in the west and rebel control in the east since shortly after fighting began there in mid-2012.
The road was cut by IS south of Khanasser despite Russian air support for government troops.
Its closure left residents of west Aleppo stranded and sent the cost of basic goods in the sector skyrocketing.