| Named By: | Ashmead in 1898 |
| Time Period: | Early Eocene |
| Location: | Canada, British Columbia. USA, Colorado - Florissant Formation |
| Size: | Unavailable |
| Diet: | Insectivore/nectar gatherer |
| Fossil(s): | Few individuals |
| Classification: | | Arthropoda | Insecta | Hymenoptera | Tenthredinidae | |
Pseudosiobla campbelli is an extinct species of sawfly in the family Tenthredinidae that is known from early Eocene Ypresian stage lake deposits near the unincorporated community of Horsefly, British Columbia.