Tomamae is located in the part of Rumoi jurisdiction in northern Hokkaido, facing the Sea of Japan to the west.

The area of Tomamae has been inhabited since the Jōmon period, and was the site of a kotan was built by the Ainu people.

Tomamae has a mayor-council form of government with a directly elected mayor and a unicameral town council of eight members.

In terms of national politics, the town is part of the Hokkaidō 10th district of the lower house of the Diet of Japan.

After the closure of the Japan National Railway Teshio Line in 1987, the town has not had any passenger rail service.