Paramacroderoides kinsellai n. sp. is described based on specimens collected from the spotted gar (Lepisosteus oculatus) from the Pascagoula River, Jackson County, Mississippi, and the Florida gar (Lepisosteus platyrhincus) from Cross Creek, Alachua County, Florida. The new species is the third recognized species of Paramacroderoides. Two Indian species of Paramacroderoides, originally described within Pseudoparamacroderoides, are transferred into Macroderoides. Paramacroderoides kinsellai n. sp. differs from Paramacroderoides echinus in having a much longer body, greater body width/length ratio, ovary situated at a significant distance from the cirrus sac rather than immediately posterior to it, and anterior margin of vitellaria at a significant distance posterior to ventral sucker. The new species differs from Paramacroderoides pseudoechinus in having a much longer body, greater body width/length ratio, ovary situated at a significant distance from the cirrus sac rather than immediately posterior to it, anterior margin of vitellaria at a significant distance anterior to ovary, vitellaria extending further posteriorly, and relative position of the intestinal bifurcation. The generic diagnosis of Paramacroderoides is amended to incorporate features found in the new species. This is the first record of a species of Paramacroderoides from the spotted gar and the first record from any host in Mississippi. Comparison of more than 2,300 base-pair sequences of nuclear rDNA (partial 18S, complete ITS region, and partial 28S) of 3 specimens from Florida and 2 specimens from Mississippi revealed only 1 base-pair difference between specimens collected in the 2 areas from the 2 host species. Sequence comparison between P. kinsellai n. sp. and previously published sequences of 3 Macroderoides species revealed that the levels of divergence between members of Paramacroderoides and Macroderoides are not much higher than levels of divergence among some species of Macroderoides.