| Named By: | J. A. Long, K. Trinajstic, G. C. Young & T. Senden in 2008 |
| Time Period: | Late Devonian, 380 Ma |
| Location: | Australia - Gogo Formation |
| Size: | About 28 centimetres long |
| Diet: | Carnivore |
| Fossil(s): | Well preserved pregnant individual with soft tissue impressions |
| Classification: | | Chordata | Gnathostomata | Placodermi | Ptyctodontida | Ptyctodontidae | |
Materpiscis (Latin for mother fish) is a genus of ptyctodontid placoderm (a class of extinct, superficially shark-like armored fishes) from the Late Devonian located at the Gogo Formation of Western Australia. Known from only one specimen, it is unique in having an unborn embryo present inside Materpiscis, and with remarkable preservation of a mineralised placental feeding structure (umbilical cord). This makes Materpiscis the oldest known vertebrate to show viviparity, or giving birth to live young.