Acushnet Cedar Swamp is a protected 1,100-acre swamp in Bristol County, Massachusetts, managed by the Massachusetts Department of Environmental Protection. Among the state's largest and wildest swamps, it lies with New Bedford Regional Airport along its southern edge. In 1972, the National Park Service designated it a National Natural Landmark. The swamp is significant as an outstanding example of the habitats and species found in the glaciated portion of the oak-chestnut forest, and it has also been identified as old-growth forest.