The genus Aesculus (/ˈɛskjʊləs/ or /ˈaɪskjʊləs/), with notable species including buckeye and horse chestnut, comprises 13–19 species of flowering plants in the family Sapindaceae. They are trees and shrubs native to the temperate Northern Hemisphere, with six species native to North America and seven to 13 species native to Eurasia. Several hybrids occur. Aesculus exhibits a classical Arcto-Tertiary distribution.
Mexican buckeye seedpods resemble the Aesculus seedpods, but belong to a different genus.