Alva is an unincorporated community and census-designated place (CDP) in Lee County, Florida, United States, situated on the Caloosahatchee River. The population was 2,725 at the 2020 census, up from 2,596 at the 2010 census. It is part of the Cape Coral-Fort Myers, Florida Metropolitan Statistical Area.

The Caloosahatchee River is a river on the southwest Gulf Coast of Florida in the United States, approximately 67 miles (108 km) long. It drains rural areas on the northern edge of the Everglades, east of Fort Myers. An important link in the Okeechobee Waterway, a manmade inland waterway system of southern Florida, the river forms a tidal estuary along most of its course and has become the subject of efforts to restore and preserve the Everglades.