The word Miami is related to the word Myaamia (click the word to go to the online dictionary and hear it pronounced). Myaamia means “downstream person” though we often translate it into the plural “people.” In the distant past, this was a term that other indigenous peoples applied to us, but over time we began to use it for ourselves. It literally describes our location as downstream on a river. This could be a reference to the Wabash River in Indiana, the St. Joseph River (in southwestern Michigan and western Indiana), or to some unknown river in our distant past. There is no known story that indicates clearly which river the name references. What we do know is that the name stuck, and by the time the French arrived in North America, the term was widely used by Myaamia community members and other indigenous groups.
Across the Midwest and the West the word Miami is still found on rivers, towns, counties, schools, and parks. This phenomenon is not surprising as most of these places fall within Myaamionki: the places that the Myaamia have called and continue to call home (Oklahoma, Kansas, Indiana, Illinois, Wisconsin, Michigan, and Ohio). However, we did not give our name directly to these places. The Miami name was placed there by outsiders, either other indigenous groups or Europeans, who associated these places with our people. Place names in our heritage language almost always reflect the ecological importance of a particular place or the story of an event that happened there in the past. For example, the Great Miami River in western Ohio likely got its current name from the indigenous peoples of eastern Ohio – Shawnee, Delaware, and Haudenosaunee – who used that river as a means to travel to our villages to the north. The British and later the Americans learned the name of this river from those groups. Our people call that river the Ahsenisiipi (Rocky River) based on an old story of the river and its rocky bottom during the dry summer months.
The lone exception to this tradition of not naming places after ourselves is the name of the town of Miami, Oklahoma. This name reportedly came from the Myaamia leader Thomas F. Richardville who had an agreement with the Ottawa chief that the Miami Tribe would name the town and the Ottawa Tribe the county. That story explains why the town of Miami sits within Ottawa County in northeastern Oklahoma.
Note: Miami, Florida does not come from the word Myaamia. The word for that city comes from one of the languages indigenous to the region and is a reference to the geography/hydrology of the area.
 David J. Costa, “Miami-Illinois Tribe Names” in John D. Nichols, ed., Papers of the 31st Algonquian Conference (Winnipeg:University of Manitoba, 2000), 50-51.