下纽约湾是指纽约湾位于纽约湾海峡以外的部分水域，亦称下湾，该湾经哈德逊峡谷直接注入大西洋，而哈德逊峡谷是一条从下纽约湾向东南方流经数百英里注入大西洋的潜水道。

下纽约湾大致上呈三角形，它的北部边界为史坦登岛和长岛，南部边界为新泽西大陆。除哈德逊河（经纽约湾海峡流入下纽约湾）外，亦有亚瑟水道、拉里坦河及一些溪流注入该湾。

亚瑟水道与拉里坦河交汇处附近的海湾区域被称为拉里坦湾。海湾进入大西洋的口门位于新泽西的桑迪胡克与长岛上的罗卡威两块陆地间之间。

历史上，下湾是纽约港的主要海运信道，近来为纽华克港-伊丽莎白航运码头的主要海运信道。

Lower New York Bay is a section of New York Bay south of the Narrows, the relatively narrow strait between the shores of Staten Island and Brooklyn. The southern end of the bay opens directly to the Atlantic Ocean between two spits of land, Sandy Hook, New Jersey, and Rockaway, Queens, on Long Island. The southern portion between Staten Island and New Jersey, at the mouth of the Raritan River, is named Raritan Bay. The Hudson Canyon, the ancient riverbed of the Hudson River which existed during the last ice age when the ocean levels were lower, extends southeast from Lower New York Bay for hundreds of miles into the Atlantic Ocean. The nearby part of the Atlantic Ocean between New Jersey and Long Island is the New York Bight.