Poquessing Creek is a 10.3-mile-long (16.6 km) creek, a right tributary of the Delaware River, that forms part of the boundary between Bucks County and the northeast section of Philadelphia, Pennsylvania. It has been part of the boundary between Bucks and Philadelphia counties since 1682. The Poquessing drains an area of approximately 21.5 square miles (56 km2) in Philadelphia, Montgomery, and Bucks counties, including portions of the municipalities of Philadelphia, Upper Southampton, Lower Southampton, Lower Moreland, and Bensalem.