Ungnadia

thumb|upright=1.5|Mexican buckeye form

Ungnadia is a genus of flowering plants in the family Sapindaceae, containing one species, Ungnadia speciosa, commonly known as the Mexican buckeye. It is native to northern Mexico, as well as Texas and southern New Mexico in the United States. The name honors Austrian ambassador Baron David Ungnad von Sonnegg, son of Andreas Ungnad von Sonnegg, who brought the horse chestnut (Aesculus hippocastanum) to Vienna in 1576, introducing the plant into western Europe.