Peritresius is an extinct genus of sea turtle from the Late Cretaceous deposits in the US Eastern Seaboard.
Two species are known, Peritresius ornatus (Leidy, 1856) and P. martini Gentry, Parham, Ehret, and Ebersole, 2018, both from Campanian-Maastrichtian age deposits in New Jersey, Alabama, and Mississippi.
Below is a cladogram from the analysis of Gentry, Ebersole & Kiernan, 2019: