It further cements President Bashar Assad's dominant position over the most populated parts of Syria after years of fighting.
The withdrawal may also be the last in a series of agreed evacuations used by the government to defeat the Takfiri insurgents by forcing them to surrender territory in return for safe passage to opposition areas in the north.
Such agreements have in recent years become a defining characteristic of Syria's seven-year war.
In the last two months alone, the United Nations says 110,000 people have been evacuated to northwestern Syria and rebel-held areas north of Aleppo.
The Syrian government has said nobody is forced to leave and those who stay must accept state rule.
The last besieged rebel area, being fully evacuated on Wednesday, is the large enclave located between the cities of Hama and Homs around the towns of Rastan, Talbiseh and Houleh.
Rebels still hold large swathes of northwest and southwest Syria that are not besieged because they border Turkey and Jordan, which have at times backed the insurgents and are guarantors of limited truces in those areas.
The only other area still surrounded by the Syrian army, in the Yarmouk Palestinian refugee camp south of Damascus, is held by Daesh terrorists.
Takfiri terrorists have lost much of the territory they once held in Syria amid sweeping gains by government forces on the ground.
In April, Syrian forces managed to retake the Eastern Ghouta and Eastern Qalamoun regions near the capital.
For years, the areas had served as a launch pad for deadly terror attacks against civilians in Damascus.