| Named By: | unavailable |
| Time Period: | Late Silurian |
| Location: | Estonia |
| Size: | Uncertain due to incomplete remains |
| Diet: | Detritivore |
| Fossil(s): | Head shield |
| Classification: | | Chordata | Osteostraci | Thyestiida | Tremataspidoidea | Tremataspididae | |
Dartmuthia is an extinct genus of primitive jawless fish that lived in the Silurian period in what is now Estonia.
To date only the creature's armored head shield (a typical trait for osteostracids) has been found. Since the mouth is positioned on the underside of the head Dartmuthia is presumed to have dwelled on the ocean floor, sucking its food into its mouth.