The Indigenous languages of the Americas are the languages that were used by the Indigenous peoples of the Americas, before the arrival of Europeans. Over a thousand of these languages are still used in the 21st century, while many more are now extinct. The Indigenous languages of the Americas are not all related to each other; instead, they are classified into a hundred or so language families and isolates, as well as several extinct languages that are unclassified due to the lack of information on them.
Many proposals have been made to relate some or all of these languages to each other, with varying degrees of success. The most widely reported is Joseph Greenberg's Amerind hypothesis; however, nearly all specialists reject it because of severe methodological flaws; spurious data; and a failure to distinguish cognation, contact, and coincidence.