Plagiodontes is a recent genus of small to medium-sized air-breathing land snails, terrestrial pulmonate gastropods in the family Cyclodontinidae.

It occurs in tropical and sub-tropical regions of South America.

Fossil record: The fossil record of Plagiodontes extends back to the Brazilian Paleocene, with a supposed specimen of Plagiodontes dentatus found in Itaboraí Basin. This same species has also been recorded from the Miocene of Uruguay and Miocene and Pleistocene of Argentina.

Species: Species within the genus Plagiodontes include:

• Plagiodontes brackebuschii (Doering, 1877)
• Plagiodontes daedaleus (Deshayes, 1851)
• Plagiodontes dentatus (Wood, 1828) - fossil from Brazil, Uruguay and Argentina, recent from Argentina - type species of genus
• Plagiodontes multiplicatus (Doering, 1877)
• Plagiodontes parodizi Pizá & Cazzaniga, 2016
• Plagiodontes patagonicus (d´Orbigny, 1835)
• Plagiodontes rocae Doering, 1881
• Plagiodontes strobelii (Doering, 1877)
• Plagiodontes weyenberghii (Doering, 1877)
• Plagiodontes weyrauchi Pizá & Cazzaniga, 2009

Synonyms:

• Plagiodontes dentata (Wood, 1828): synonym of Plagiodontes dentatus (W. Wood, 1828) (incorrect gender of species epithet)
• Plagiodontes iheringi (Pilsbry & Vanatta, 1898): synonym of Plagiodontes patagonicus (d´Orbigny, 1835)
• Plagiodontes patagonica (d´Orbigny, 1835): synonym of Plagiodontes patagonicus (d´Orbigny, 1835) (incorrect gender of species epithet)
• Plagiodontes trahyrae - from Brazil: synonym of Cyclodontina trahyrae (S. H. F. Jaeckel, 1950)