Kanmurijima (冠島) is an island in the Sea of Japan administered under Maizuru in Kyoto Prefecture. It is about 2 km from Kutsujima, a similar smaller island. Nakatsu reef (中津ぐり, Nakatsu-guri) is located just midway between islands. A breeding ground for streaked shearwaters, the island was designated a Japanese natural monument (天然記念物, tennen-kinenbutsu) in 1924. It has also been recognised as an Important Bird Area (IBA) by BirdLife International. Currently, the island is designated as Kanmurijima-Kutsujima wildlife protection area and any landing is prohibited. A recreational diving service is available though.

According to records of Tango no kuni fudoki, Kanmurijima and Kutsujima are the remains of a much larger island which submerged following an earthquake in 701 A.D. The topography of the seafloor seems to support the claim, as the steep 60-metre cliff is located underwater off the eastern coast of Kanmurijima and Kutsujima, indicating a recent crustal fault.

• Amanohashidate
• Kutsujima
• Desert island
• List of islands

• Kyoto Prefecture (in Japanese).