Serei Saophoan (properly Svay Sisophon, Khmer: សិរីសោភ័ណ; Thai: ศรีโสภณ, RTGS: Si Sophon) is the provincial capital of Banteay Meanchey, Cambodia. The city separates Cambodia's National Highway 5 and National Highway 6. Serei Saophoan is difficult to pronounce, so often the area is written transliterated as "Sisophon", even on Cambodian signs. Its population is 61,482 in the 1998 census, changing little to 61,631 in the 2008 census having been overtaken by Poipet in size.

About forty minutes from Sisophon there is a Khmer temple ruin called Banteay Chmar.