Juncus paludosus E. L. Bridges & Orzell is described and illustrated as a new species from peninsular Florida, U.S.A., occurring primarily in hardwood and cypress swamps and adjacent ditches and marshes. Although closest in diagnostic characters to J. megacephalus M. A. Curtis, it has been confused with J. polycephalus Michaux of section Iridifolii Snogerup & Kirschner based on its overall size, gross morphology, and floral characteristics. Differences between J. paludosus and other closely related species of section Ozophyllum Dumortier are discussed, and a key is provided to the group within section Ozophyllum that includes J. paludosus.