Phagomyxids are a group of obligate endoparasitic protists belonging to the subphylum Endomyxa in Cercozoa.

[1] Taxonomically, they are united under a single family Phagomyxidae, order Phagomyxida, sister to the plasmodiophores.

[2] Phagomyxids are mainly parasites of brown algae,[3] but some can parasite oomycetes.

[4] The group was created in 1993 by Cavalier-Smith, when it contained only the genus Phagomyxa.

[2] Since then, Maullinia, a genus previously in Plasmodiophoridae, has joined the phagomyxids.