Chestnut is the name for a kind of tree or the nut from the tree.

Chestnut may also be: In botany:

• American chestnut, one of the most important forest trees throughout much of the eastern United States and southeasternmost Canada
• Chestnut blight, fungal disease
• Chestnut oak, species of oak in the white oak group
• Chinese chestnut
  • Castanea mollissima, species of chestnut native to China
  • Sterculia monosperma, also known as Thai Chestnut
• Guiana chestnut, a name for Pachira aquatica
• Horse chestnut, member of the genus Aesculus
• Japanese chestnut, species of chestnut from Japan and South Korea
• Malabar chestnut, a name for Pachira aquatica
• Swamp chestnut oak, species of oak in the white oak section Quercus
• Sweet chestnut, species of chestnut from southeastern Europe and Asia Minor

In geography:

• Chestnut, Illinois, United States
• Chestnut Grove, North Carolina, United States

In zoology:

• Chestnut (coat), color of horse
• Chestnut (horse anatomy), on the legs of horses
• Chestnut Dunnart, dunnart that was described by Van Dyck in 1986
• Chestnut Sparrow, sparrow that likes dry savanna
• Chestnut Teal, dabbling duck found in southern Australia
• Chestnut Woodpecker, bird from South America from Colombia, Venezuela and the Guianas south to Ecuador, Bolivia and northern Brazil, and on Trinidad
• Horse-chestnut leaf miner, a moth

In other fields:

• Chestnut (color), reddish brown
• Chestnut hair, reddish brown hair
• Operation Chestnut, failed British raid by 2 Special Air Service
• Chestnut (joke), British slang for an old or stale joke
• Chestnut (music), piece of music that has been played so much that everyone has grown tired of it

People with the family name Chestnut:

• Cyrus Chestnut, jazz pianist
• Jacob Chestnut, one of the two United States Capitol Police officers killed in the line of duty on July 24, 1998
• Joey Chestnut, competitive eater from San Jose, California
• Morris Chestnut, American movie and television actor