Kamiiso (上磯郡; -gun) is a district located in Oshima Subprefecture, Hokkaido, Japan.

As of 2004, the district has an estimated population of 48,470 and a density of 71.18 persons per km². The total area is 680.95 km².

Towns

• Kamiiso
• Kikonai
• Shiriuchi