Helveticosauridae is an extinct family of basal marine reptiles known from the Middle Triassic (Anisian-Ladinian boundary) of southern Switzerland and northern Italy. The type species of the family is Helveticosaurus zollingeri, named by Bernhard Peyer in 1955 based on a single nearly complete specimen T 4352 collected at Cava Tre Fontane from the Anisian-Ladinian boundary of Monte San Giorgio, Switzerland. Peyer (1955) considered the species to be a very distinctive member of the order Placodontia, and thus erected Helveticosauridae as well as the superfamily Helveticosauroidea to contain it within Placodontia.