Bibai (美唄市, Bibai-shi) is a city located in Sorachi Subprefecture, Hokkaido, Japan.

The name Bibai is derived from Ainu word "pipa o i", meaning "Place (swamp) with many cockscomb pearl mussels".

[1][2] At its peak, Bibai was a coal town that produced over a million tons annually.

However, ever since the mine was closed in 1972, the city has suffered a slowly declining population.

[4] Per Japanese census data,[7] the population of Bibai has declined by more than half over the past half-century.