The North River is shown in red, between New Jersey and Manhattan.

North River describes the southernmost portion of the Hudson River, between the states of New Jersey and New York in the United States of America.

There is argument as to how much of the Hudson River estuary is the North River. Some include the area from the mouth of the river at Upper New York Bay to its junction with the Harlem River, the latter actually a tidal strait, at the northern end of Manhattan Island.

In commercial usage, however, the North River is the part of the river from the Hudson River's mouth to approximately the "bend" where the Hudson River turns from south-southwest to south at about 30th Street. The piers below this point were known as North River piers and were designated in shipping notices as (for example) "Pier 14, N.R."

Hagstrom Company maps, generally considered the standard in the New York Metropolitan Area, used to designate this lower part of the Hudson as North River and above that as Hudson River. Recent editions of these maps, now that the Hagstrom Company is part of the Langenschedit Publishing Group, omit the North River name.

The origin of the name North River is generally attributed to the Dutch, in describing the names of the rivers in their American Nieuw Nederland colony as designating what is now the Hudson as the North River, and the Delaware as the South River.