North American populations of Gull-billed Terns (Gelochelidon nilotica) are thought to winter in low numbers throughout Central America, with highest single-site concentrations of up to 200 individuals known from the Panama Canal zone. This paper presents information on a previously unknown stopover and wintering site in southern Honduras, where up to 1,640 individuals, approximately 20% of the entire North American metapopulation, are present during the non-breeding season. This site may be of key importance to full cycle conservation of declining North American populations. Information on habitat use in the eastern Gulf of Fonseca is also included.