Ceratium furca is a species of marine dinoflagellates.
This species has a straight body which is 70-200 üm long and 30-50 üm wide, with the epitheca gradually tapering into an anterior horn. C. furca has long spines, and is an "armoured" species with a theca of thick cellulose plates. The cells are nearly flat, with the ventral side concave and the dorsal side being convex.
Ceratium furca is found worldwide.