The Ponto-Caspian Cordylophora caspia (Pallas, 1771) is a euryhaline, invasive hydroid reported to occur for the first time in Missouri. We collected a colony of C. caspia on 3 December 2013 from substrate exposed to flow at an inspection area of Bagnell Dam, which impounds Lake of the Ozarks (22,460 ha) in the Osage River drainage basin. Although the ultimate ecological consequences associated with C. caspia invasion of freshwaters in North America are unknown, C. caspia is capable of fouling water management infrastructures and, therefore, monitoring the occurrence and distribution of this invasive hydrozoan is warranted.