Algerine Swamp Natural Area is an 84-acre (34 ha) protected area in Lycoming and Tioga Counties, Pennsylvania, United States. It is part of Tiadaghton State Forest, and has also been named a National Natural Landmark.

The Natural Area features black spruce and balsam fir trees, both of which are rare in Pennsylvania, and is centered on a glacial bog. The area includes other tree species that are more common to the north in Canada, as well as a population of pitcher plants. The area can be reached via the nearby Long Branch Trail, a short distance north of a junction with the long-distance Black Forest Trail.