is a city and port located in Iburi, Hokkaidō, Japan. Though its name implies a small, idyllic town, it is considered the largest city in the Iburi Subprefecture. As of 2008, the estimated population was 173,504 and the density of 310 persons per km². The total area is 561.49 km².
The sister city for Tomakomai is Napier of Hawke's Bay, New Zealand.