Over the past 30 years, cold events and disease have reduced much of the live Acropora cervicornis (Staghorn Coral) in Dry Tortugas National Park (DTNP), FL to fields of coral rubble. It is unclear how the resulting loss of three-dimensional reef structure has affected density and distribution of reef-dependent damselfishes. We compared densities of Stegastes adustus (Dusky Damselfish), Stegastes leucostictus (Beaugregory Damselfish), Microspathodon chrysurus (Yellowtail Damselfish), Stegastes planifrons (Three-spot Damselfish) and Stegastes variabilis (Cocoa Damselfish) inhabiting DTNP's last live Staghorn Coral formation with densities from surrounding coral rubble. Live Staghorn Coral supported a 65% higher damselfish density compared to coral rubble. Density of Dusky, Cocoa, Beaugregory, Yellowtail and Three-spot Damselfish on coral rubble (0.11, 0.58, 0.74, 0.02, and 0.06 fish/m², respectively) was less than that found on living Staghorn Coral colonies (2.03, 0.45, 0.25, 0.50, and 0.96 fish/m², respectively). Dusky Damselfish dominated the live Staghorn Coral site, while Cocoa and Beaugregory Damselfish dominated the coral rubble site. Juvenile density was ten times greater on coral rubble than on live Staghorn Coral, whereas adults had highest densities on live Staghorn Coral.