Lake Conlin is a lake in Osceola County, Florida, United States just north of Old U.S. Route 192 near Holopaw. It is the source of the Econlockhatchee River, Cat Island Swamp, and the Econlockhatchee River Swamp. These bodies of water flow northward to the St. Johns River, 101 kilometres (63 mi) downstream. The source of the wetlands are located at the northeastern portion of the lake. The size is 25.42 square kilometres (2,542 ha), and 11 kilometres (6.8 mi) in diameter.