Echigo Province (越後国 Echigo no kuni?) was an old province in north-central Japan, on the shores of the Sea of Japan. It bordered on Uzen, Iwashiro, Kōzuke, Shinano, and Etchū Provinces. It corresponds today to Niigata Prefecture, minus the island of Sado.
Its abbreviated form name was Esshū (越州?), with Echizen and Etchū Provinces. Under the Engishiki classification system, Echigo was ranked as one of the 35 "superior countries" (上国) in terms of importance, and one of the 30 "far countries" (遠国) in terms of distance from the capital.
Echigo and Kōzuke Province were known as the Jōetsu region.
In the late 7th century, during the reign of Emperor Mommu, the ancient province of Koshi Province (越国 or 古志国 Koshi no kuni?) was divided into three separate provinces: Echizen, Etchū, and Echigo. The new Echigo Province consisted of Iwafune and Nutari Districts, and was one of two border provinces of the Yamato state with the Emishi (the other being Mutsu). In 702, Echigo was given the four districts of Kubiki, Koshi, Uonuma and Kanbara from Etchū. When Japan extended its territory northward in 708, Dewa District was established under Echigo. But this district was transformed into Dewa Province in 712. Sado Province was temporarily merged with Echigo between 743 and 752. Since the division of Sado in 752, the territory of Echigo remained constant to the Meiji period.