Rhizosmilodon is an extinct genus of saber-tooth cat of the subfamily Machairodontinae that lived during the Early Pliocene and was discovered in the U.S. state of Florida.

[2][3] The locality of Rhizosmilodon suggests a North American origin of the Dirk-Toothed cats.

The derived traits include various measurements of the incisors, p3, p4, and m1 teeth, with the lower canine being laterally compressed.

[1] Serrations only on the canine teeth support the placement of Rhizosmilodon within the tribe Smilodontini rather than the scimitar-toothed Homotherini.

The severity of the serrations place Rhizosmilodon as a more ancestral genus than Megantereon and Smilodon.