Remains of giant fossil coelacanth fish are relatively common in Upper Cretaceous strata (late Santonian to early Campanian age) in Alabama and Georgia. These are penecontemporaneous with the youngest reported fossil coelacanths from any global location and ∼135 m.y. younger than the last coelacanth fish reported from North America. A coelacanth coronoid fragment from New Jersey, apparently from the same taxon, is of latest Campanian or Maastrichtian age and is the youngest known definite coelacanth fossil. The species reconstructs to 3.5 m, which is as large as any known coelacanth. The name Megalocoelacanthus dobiei is proposed for this new coelacanth, which is also the last known member of the Glade that includes the extant Latimeria.