| Named By: | Edward Drinker Cope in 1882 |
| Time Period: | Early Eocene |
| Location: | Across Eurasia and North America |
| Size: | Up to 50 centimetres long |
| Diet: | Herbivore |
| Fossil(s): | Hundreds of specimens |
| Classification: | | Chordata | Mammalia | Artiodactyla | Dichobunidae | |
| Also known as: | | Gujaratia | Trigonolestes | |
Diacodexis is an extinct genus of small herbivore mammal belonging to the family Dichobunidae which lived in North America, Europe and Asia from 55.4 mya--46.2 mya. and existing for approximately 9.2 million years.