Tomakomai (苫小牧市, Tomakomai-shi) is a city and port in Iburi Subprefecture, Hokkaido, Japan.

The city is known for its high catch of Arctic surf clams.

The name of Tomakomai is derived from Ainu words "to" and "makomai", meaning "Marsh" and "River which goes into the depths of the mountain", respectively.

[1][2] Mount Tarumae is located in the northwest of Tomakomai and belongs to Shikotsu-Tōya National Park.

[5] Tomakomai is home to the Asia League Ice Hockey team Red Eagles Hokkaido.