The Nicely Formation is a fossil-bearing geologic formation in eastern Oregon found in Crook, Grant, and Harney counties. Dating to the Pliensbachian stage of the Early Jurassic, it preserves evidence of marine life from that time. Its known fossils include radiolaria, which are microscopic marine organisms, and ichthyosaur remains identified at least in indeterminate form. These finds make the formation an important source of evidence for life in Oregon during the Early Jurassic and place it among the state's fossiliferous stratigraphic units.