Great Ditch is a drainage ditch that drains areas of the Pigeon Swamp State Park in New Jersey in the United States.

Great Ditch starts at 40°23′5″N 74°28′57″W / 40.38472°N 74.48250°W / 40.38472; -74.48250,[1] in the Pigeon Swamp State Park.

It flows west, crossing Fresh Ponds Road and Route 130 before joining another stream at 40°23′39″N 74°30′27″W / 40.39417°N 74.50750°W / 40.39417; -74.50750[1] which drains into the Lawrence Brook.

This canal's purpose is to drain sections of the Pigeon Swamp to prevent flooding of Deans Rhode Hall Road, which passes through the swamp.