The Vectis Formation is a geological formation on the Isle of Wight and Swanage, England whose strata were formed in the Barremian, approximately 125 million years ago.

[1][2] The environment of deposition was that of a freshwater coastal lagoon with occasional marine influence after the early Aptian marine transgression, transitioning from the floodplain environment of the underlying Wessex Formation.

The primary lithology is of laminated grey mudstones.

It is overlain by the fully marine Atherfield Clay Formation, part of the Lower Greensand Group.

Dinosaur remains are among the fossils that have been recovered from the formation.