Protozoa Goldfuss, 1818 - protozoans
   Phylum Sarcomastigophora Honigberg & Balamuth, 1963
     Subphylum Mastigophora Diesing, 1866 - flagellates
       Class Zoomastigophorea - "animal-like" flagellates see Phylum Zoomastigina
         Order Choanoflagellida Kent, 1880 - choanoflagellates see Class Choanoflagellatea Cavalier-Smith, 1998
         Order Diplomonadida Wenyon, 1926 - diplomonads
         Order Hypermastigida Grassi, 1911 - hypermastigids see Class Hypermastigia
         Order Kinetoplastida Honigberg, 1963 - kinetoplastids see Order Kinetoplastea Honigberg, 1963
         Order Oxymonadida Grassé, 1952 - oxymonads
         Order Proteromonadida Grassé, 1952
         Order Retortamonadida Grassé, 1952 - retortamonads
         Order Trichomonadida Kirby, 1947 - trichomonads