Abrothrix longipilis, also known as the long-haired grass mouse or long-haired akodont, is a species of rodent in the family Cricetidae. It is found in central and southern Argentina and Chile. The southern Chilean "Abrothrix sanborni" may not be distinct from this species.
The long-haired grass mouse, abrothrix longipilis, and the long-haired akodont are all terms that refer to the same animal. 