The fossil insect collection housed at the Illinois Natural History Survey (INHS) on the University of Illinois Urbana-Champagne campus is represented by both amber inclusions and rock compressions. The foundation of the collection is the historically significant Milton Sanderson amber collection, comprising large quantities of Early Miocene amber from the Dominican Republic as well as smaller samples of copal from Madagascar and Colombia. Also present in the collection are a small number of inclusions in Eocene Baltic amber, as well as compression fossils from the Carboniferous (mid-Pennsylvanian) Mazon Creek deposit, the Cretaceous Crato Formation of Brazil, the Eocene Green River and Florissant Formations of Colorado, and the Oligocene Renova Formation of Montana, as well as specimens preserved in asphalt from the Pleistocene tar pits of southern California (La Brea and McKittrick). The majority of the non-Sanderson collection comes from recently developed, active research collections that are continually growing. Many fossil insect specimens housed in the INHS collection represent new and undescribed taxa currently under study by INHS scientists. Their goal is to digitize ~10,000 specimens.