| Ampthill Clay | |
| Type: | Geological formation |
| Age: | Oxfordian |
| Period: | Oxfordian |
| Prilithology: | Mudstone |
| Otherlithology: | Limestone, Marl |
| Region: | England |
| Unitof: | Ancholme Group |
| Underlies: | Kimmeridge Clay |
| Overlies: | West Walton Formation or Corallian Group |
| Thickness: | 0-90 m |
The Ampthill Clay is a Mesozoic geologic formation in southern England. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.[1]