Franconiasaurus (meaning "Franconia reptile") is an extinct genus of basal plesiosauroid plesiosaurs from the Early Jurassic of Germany.

[1] In 2024, Sachs, Eggmaier & Madzia described Franconiasaurus brevispinus as a new genus and species of plesiosauroid based on these fossil remains.

The generic name, "'Franconiasaurus", combines Franconia, after the Bavarian region of the type locality, with the Greek "σαῦρος" ("sauros"), meaning "reptile".

The specific name, "brevispinus", references the short neural spines of some of the cervical and dorsal vertebrae.

[1] In their phylogenetic analyses, Sachs, Eggmaier & Madzia (2024) recovered Franconiasaurus as a plesiosauroid member of the Plesiosauria, as the sister taxon to the Cryptoclidia.