The maritime boundary between Russia (formerly USSR) and North Korea (DPRK) is 214 nautical miles long and traverses the Sea of Japan (East Sea) on a generally southeasterly bearing. The territorial sea boundary, which emanates from the mouth of the Tumen River, was initially established in 1985 as part of the land boundary Agreement between the USSR and North Korea.

In 1986, North Korea and the USSR agreed to a continental shelf and exclusive economic zone boundary in the Sea of Japan. While the maritime boundary has generally been uncontentious, in recent years issues have arisen over rights to resources, especially fishing, and the trespassing of foreign vessels. Despite these challenges, relations remain positive between Russia and North Korea.