The Maina Indians are a group of tribes who lived or live along the north bank of the Marañón River in South America. They spoke varieties of the Omurano language and resided along the North bank of the Marañón.
The Maina were among the first tribes of the upper Amazon region to have been evangelized by the Catholic Church, leading to the naming of several jurisdictions and areas after the tribe, including the province of Mainas, which included the larger part of the present Ecuador and northern Peru, east of the main Cordillera, including the basins of the Huallaga and Ucayali.
The Maina Indians were one of many older cultures to play with rubber balls as toys. They called it "caucho" which combined the words "caa" (wood) and "ochu" (to cry), made by extracting the sap from a tree they called "heve" and letting it dry into a playable solid that we today call rubber.