The Shrewsbury River is a short stream and navigable estuary, approximately 8 mi (13 km) long, in central New Jersey in the United States.
It extends ENE from its head of navigation at Oceanport to its confluence with the Navesink River estuary, then entering 1 mi (1.6 km) north in a narrow channel to Sandy Hook Bay at Highlands. The south shore runs about the entire length of the northern border of Long Branch. The estuary is protected from the open Atlantic Ocean on its eastern side by a long barrier peninsula that extends north to become Sandy Hook. Jersey Shore resort communities on the peninsula include Monmouth Beach and Sea Bright. On the inner side of the estuary, the community of Rumson on the end of the peninsula separating the Shrewsbury and Navesink estuaries is among the wealthiest communities in the United States.
The estuary provides a popular marina for pleasure craft and recreational fishing. Marine species like Fluke (summer flounder), striped bass, bluefish and weakfish are popular fish targeted by local anglers.
Coordinates: 40°20′36″N 73°59′52″W / 40.3432306°N 73.9976946°W