Humboldt can refer to:

* Alexander von Humboldt, a German natural scientist
* Wilhelm von Humboldt (his brother), a linguist, philosopher, and diplomat

Or any of the many things named for them:

Named for Alexander von Humboldt

Places in California, U.S.

* Humboldt Bay in California
* Humboldt County, California
* Humboldt Hill
* Humboldt Redwoods State Park in California
* Humboldt State University in California

Places in Nevada, U.S.

* Humboldt County, Nevada
* Humboldt, Nevada
* East Humboldt Range in Nevada
* West Humboldt Range in Nevada
* Little Humboldt River in Nevada
* Humboldt Wildlife Management Area in Nevada
* Humboldt-Toiyabe National Forest in Nevada
* Lake Humboldt in Nevada
* Humboldt River in Nevada
* Humboldt Range in Nevada
* Humboldt Salt Marsh in Nevada
* Humboldt Sink in Nevada

Other places in the U.S.

* Humboldt Peak, Colorado
* Humboldt, Illinois
* Humboldt Park, Chicago, Illinois
* Humboldt, Iowa
* Humboldt County, Iowa
* Humboldt, Kansas
* Humboldt Township, in Marquette County, Michigan
* Humboldt, Minnesota
* Humboldt Township, in Clay County, Minnesota
* Humboldt, Nebraska
* Humboldt Municipal Airport (HBO) in Nebraska
* Humboldt, South Dakota
* Humboldt, Tennessee
* Humboldt, Wisconsin

Other places

* Núcleo Pioneiro de Humboldt, scientific center in the Amazon Basin
* Colégio Humboldt, German school in São Paulo, Brazil
* Colegio Alemán Alexander von Humboldt, German School in Lima, Peru
* Colegio Alemán Alexander von Humboldt, German School in Mexico-City
* Humboldt, Saskatchewan, Canada
* Guevea de Humboldt, Oaxaca, Mexico

Organizations

* Alexander von Humboldt Foundation, a German foundation for the promotion of international research cooperation

Natural formations

* Humboldt Mountain Range in Antarctica
* Humboldt Mountains in China
* Parque Nacional Alejandro de Humboldt in Cuba
* Humboldt Glacier in Greenland
* Teluk Humboldt in Indonesia
* Mont Humboldt in New Caledonia
* Humboldt Bay in New Guinea
* Humboldt Mountains in New Zealand
* Mount Humboldt in New Zealand
* Mirador Humboldt in Tenerife
* Humboldt peak in Venezuela
* Humboldt Current or Peru Current of the Pacific

Animals

* Humboldt's Big-eared Brown Bat (Histiotus humboldti)
* Humboldt's Woolly Monkey (Lagothrix lagotricha)
* Humboldt's squirrel monkey (Saimiri sciureus cassiquiarensis)
* Humboldt Penguin (Spheniscus humboldti)
* Humboldt's Hog-nosed Skunk (Conepatus humboldtii)
* Humboldt's Black-headed Uakari (Cacajao melanocephalus)
* Yeast species (Pichia humboldtii)
* Humboldt sucker (Catostomus occidentalis humboldtianus)
* Humboldt Squid (Dosidicus gigas)

Plants

* Anthurium (Anthurium humboldtianum Kunth.)
* Bladderwort species (Utricularia humboldtii)
* Cactus species (Mammillaria humboldtii)
* Humboldt's Lily (Lilium humboldtii)
* Mushroom species (Tricholomopsis humboldtii)
* South American Oak (Quercus humboldtii)
* Orchid species (Schomburgkia humboldtii)

In space

* 54 Alexandra, asteroid
* Catena Humboldt on the Moon
* Mare Humboldtianum, lunar crater

Named for Alexander and Wilhelm von Humboldt

* Humboldt University of Berlin (Humboldt-Universität zu Berlin)
* Humboldt Museum of Natural History (Museum für Naturkunde), part of the University

Unknown provenance

* Humboldt State University, Humboldt County, California (named for the county where it is located)
* Humboldt Exchange, Community Currency, Democracy Unlimited