| Named By: | Dore & Reid in 1965 | 
| Time Period: | Cambrian Stage 2-Middle Cambrian | 
| Location: | Antarctica - Cape Melville Formation. Australia - Coobowie Limestone Formation, Kulpara Formation, Parara Limestone Formation. China. Jordan - Burj Formation | 
| Size: | Unavailable | 
| Diet: | unavailable | 
| Fossil(s): | Numerous specimens | 
| Classification: | | Animalia | Coeloscleritophora | Chancelloriida | Chancelloriidae | | 
| Also known as: | | Dimidia | Onychia | Rosella | Zhurinia | | 
Allonnia is a genus of coeloscleritophoran known as complete scleritomes from the Middle Cambrian Burgess Shale. It is also a constituent of the small shelly fauna.
Its earliest occurrence in Yunnan dates to the Upper Meishucunian (~ Tommotian / Cambrian Stage 2)