Flagellates are single-celleded protists with one or more flagella, whip-like organelles often used for propulsion. Originally they were grouped together as the class or phylum Mastigophora, but the different lines do not appear particularly closely related. These include:
- Retortamonads
- Diplomonads
- Oxymonads
- Parabasalia
- Jakobids
- Heterolobosea (amoeboflagellates, etc)
- Euglenozoa (kinetoplastids, euglenids, etc)
- Ebriids
- Ellobiopsids
- Dinoflagellates
- Haptophytes
- Stramenopiles (golden algae, bicosoecids, etc)
- Cryptomonads
- Green algae
- Choanoflagellates