Sister cities of Monbetsu, Hokkaido

Monbetsu (紋別市, Monbetsu-shi) is a city located in Okhotsk Subprefecture, Hokkaido, Japan; on the Sea of Okhotsk. The name comes from Ainu Mopet (Quiet River). It is often called Okhotsk-Monbetsu to distinguish it from the town of Monbetsu in Hidaka Subprefecture (different kanji, but same reading).

Most of Monbetsu's economy is dedicated to fishing for cold-water species such as crab. The crab from Monbetsu is reputably the best in Japan, and is such a source of town pride that a sculpture of a crab claw nearly 10 m tall was built on the waterfront.

Monbetsu is famous for drift ice, a yearly phenomenon which reaches the city every January or February from the northern Sea of Okhotsk. As such, the city has taken on the drift ice as its symbol and has become a center for research on sea ice generally, with an international conference held in February (usually the time of peak sea ice) each year. There is also a yearly Drift Ice Festival that coincides with the Sapporo Snow Festival. The festival features impressive sculptures built out of drift ice along with a large ice maze. Additionally, the Okhotsk Tower is a facility where one can observe sea ice from both high above, and from below the ocean. It is complete with an information center and aquarium. An icebreaker, the Garinko II, departs from nearby and makes regular sightseeing cruises through the drift ice during the winter. Mombetsu is also home to the newly built Drift Ice Museum, which covers all aspects of sea ice and features a sub-zero room and "frozen aquarium" of various fish preserved in ice.

During the summertime, when the sea ice melts, sailors from Russia are a common sight in the city. Some local businesses have banned Russian visitors for their supposed "unruly" behavior, which has led some activists to criticize Monbetsu as a hotbed of racial discrimination. (See also: Ethnic issues in Japan.)

As of 2008, the city has an estimated population of 25,678 and a population density of 30.9 persons per km² (80.0 persons per sq. mi.). The total area is 830.70 km² (320.74 sq mi).

Monbetsu does not have passenger rail service. There are buses to Sapporo and Asahikawa, as well as a daily flight to Tokyo from Monbetsu Airport.