Willamette (/wᵻlˈlæmᵻt/ wil-LAM-it), from the Clackamas language of the Columbia River, Oregon, can refer to:

A toponym of the U.S. state of Oregon:

The Willamette Meteorite, officially named Willamette, is an iron-nickel meteorite discovered in the U.S. state of Oregon. It is the largest meteorite found in North America and the sixth largest in the world. There was no impact crater at the discovery site; researchers believe the meteorite landed in what is now Canada or Montana, and was transported as a glacial erratic to the Willamette Valley during the Missoula Floods at the end of the last Ice Age (~13,000 years ago). It was long held sacred by indigenous peoples of the Willamette Valley, including the federally recognized Confederated Tribes of the Grand Ronde Community of Oregon (CTGRC). The indigenous peoples referred to this stone with the name Tomonowos (the visitor from the sky).

The meteorite is currently on display at the American Museum of Natural History, which acquired it in 1906. Having been seen by an estimated 40 million people over the years, and given its striking appearance, it is among the most famous meteorites known. In 2005, the Confederated Tribes of the Grand Ronde Community of Oregon sued to have the meteorite returned to their control but they were unsuccessful.