Shiashkotan (Russian: Шиашкотан) (Japanese: 捨子古丹島; Shasukotan-tō) is an uninhabited volcanic island near the center of the Kuril Islands chain in the Sea of Okhotsk in the northwest Pacific Ocean, separated from Ekarma by the Ekarma Strait.

The island appears on an official map dated 1644, showing the feudal territories of the Matsumae Domain in Edo period Japan; these holdings were confirmed by the Tokugawa shogunate in 1715.

When the Kuril Islands were returned to the Empire of Japan, per the 1875 Treaty of Saint Petersburg, no inhabitants remained on Shiashkotan, as they moved north to Russian Kamchatka.

In 1893, a settlement was attempted by nine members of the Chishima Protective Society, led by Gunji Shigetada; however, when a ship called on the island a year later, five of the colonists had already died, and the remaining four were critically ill with beri-beri.

After World War II, the island came under the control of the Soviet Union, and is now administered as part of the Sakhalin Oblast of the Russian Federation.