Sanjō (三条市, Sanjō-shi) is a city located in Niigata Prefecture, Japan.

Sanjō has a Humid climate (Köppen Cfa) characterized by warm, wet summers and cold winters with heavy snowfall.

After the start of the Meiji period, the area was organised as part of Minamikanbara District, Niigata.

[5][6] Sanjō has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 22 members.

It is also one of the municipalities where a local Factory Festival takes place once per year in October (Kouba no Saiten).