Keewaydin Island is a primary barrier island located off the coast of Naples, in Collier County, Florida, United States. It can be reached only by boat. It is managed by the State of Florida's Coastal Office, in cooperation with NOAA, within the Rookery Bay National Estuarine Research Reserve. Keewaydin Island is monitored nightly for Loggerhead turtle nesting activity by The Conservancy of Southwest Florida.