The North Bismarck plate is a small tectonic plate located in the Bismarck Sea off the northeast coast of New Guinea.

[3][2] At one time it was called the Manus plate, but this term was later used for a modelled microplate at the south east boundary of the North Bismarck plate.

[1]: 22 The plate contains most of the Melanesian arc volcanoes, related to current and historic arc volcanism, except those of New Britain which are on the active South Bismarck plate.

[4] The BSSL is a very seismically active area but the assigned shallow earthquakes tend to be less than magnitude 7.

[2]: 68  There are a few shallow low intensity earthquakes to the south/south west of these trenches on a line of the old arc that extends from the smaller northern Admiralty Islands in the west through to Mussau Island and beyond.