* Mohawk
* Oneida
* Onondaga
* Cayuga
* Seneca
* Tuscarora
These nations historically spoke Iroquoian languages, a family of languages that includes their own unique languages and some other Indigenous languages in the region.
It's important to note that each of the Six Nations has its own distinct language within the Iroquoian family. So, they didn't speak one singular language, but a group of related languages.