was a old province of Japan on the island of Hokkaido. The history of the province started in 1869 and ended in 1882.
The boundaries of this ancient province are generally mirrored in what are today called Oshima Subprefecture and Hiyama Subprefecture.
History
After 1869, the northern Japanese island was known as Hokkaido. Regional subdivisions were established. Oshima Province was one of the new entities which were created in 1869.
In the Meiji period, the provinces of Japan were converted into prefectures. The maps of Japan including Oshima Province were reformed in the 1870s.
In 1882, Oshima and the other ten provinces of Hokkaido were reorganized as Hakodate Prefecture, Sapporo Prefecture and Nemuro Prefecture.