| Named By: | P. E. Olsen in 1979 |
| Time Period: | Late Triassic |
| Location: | USA, Arizona - Chinle Formation, New Jersey - Lockatong Formation, and North Carolina - Cow Branch Formation |
| Size: | Roughly about 50-60 centimetres long |
| Diet: | Carnivore/Piscivore |
| Fossil(s): | Several individuals |
| Classification: | | Chordata | Reptilia | Protorosauria | Tanystropheidae | |
Tanytrachelos is an extinct genus of tanystropheid archosauromorph reptile from the Late Triassic of the eastern United States. It contains a single species, Tanytrachelos ahynis, which is known from several hundred fossil specimens preserved in the Solite Quarry in Cascade, Virginia. Fossils of Tanytrachelos are found in a series of lakebed sediments that were deposited over the course of about 350 thousand years. Some fossils are very well-preserved and include the remains of soft tissues.