Lake Poinsett is a lake in Brevard County, Florida, United States, near Rockledge and Cocoa, with small portions in Orange County and Osceola County. It is the second-largest lake in Brevard County, after Lake Washington, though it is actually the smallest lake in Osceola County. It is the widest lake in Brevard County, with a distance of 5 miles (8 km) at its widest point. At the eastern portion of the lake, a channel connects the lake to Lake Florence and Barnett Lake.