Humboldt State University (HSU, Humboldt State, or Humboldt) is a public university in Arcata, California. It is the northernmost campus of the 23-school California State University (CSU) system. The main campus, situated hillside at the edge of a coast redwood forest, has commanding views overlooking Arcata, much of Humboldt Bay, and the Pacific Ocean. The college town setting on the California North Coast, 8 miles (13 km) north of Eureka, 279 miles (449 km) north of San Francisco, and 654 miles (1052.51 km) north of Los Angeles is notable for its natural beauty. It is the most westerly four-year university in the contiguous United States.

The university is divided into three colleges: the College of Arts, Humanities, and Social Sciences; the College of Natural Resources and Sciences; and the College of Professional Studies. It offers 48 types of bachelor's degrees, 12 different master's degrees, 61 minors, and 13 credential programs. HSU does not offer doctoral degrees.

In addition to the main campus, HSU has multiple off-campus facilities and education-related properties, including an ocean-side marine biology research center, a wildlife care facility, a public natural history museum, a public art gallery, a bay-side aquatics facility, a mountain-top astronomy observatory, an ocean-going marine research and teaching vessel (Coral Sea), and a demonstration forest (Arcata Community Forest).