any member of the zooflagellate protozoan order Hypermastigida. Hypermastigotes are complex, uninucleate, multiflagellate organisms that are parasitic or symbiotic in the digestive systems of termites, cockroaches, and woodroaches. Hypermastigotes' numerous flagella are arranged in circles, tufts, spirals, or transverse rows. Feeding occurs by parasitic absorption through the body surface or the ingestion of wood, starch, or other food by cytoplasmic extensions (pseudopodia). Reproduction is asexual (by division) or sexual. Encystment sometimes occurs. In the genus Trichonympha encystment and sexual reproduction are initiated by the molting of the host woodroach.

Representative genera are Lophomonas in the cockroach and Holomastigotoides in the termite. Hypermastigotes are essential to termites' digestive processes, and the protozoans may account for half the total weight of the host. Some hypermastigotes are able to survive only in certain termite species.