The Pacific States form one of the nine geographic divisions within the United States that are officially recognized by that country's census bureau.

There are five states in this division — Alaska, California, Hawaii, Oregon, Washington — and, as its name suggests, they all have coastlines on the Pacific Ocean (and are the only states that border that ocean). Additionally, Nevada and Arizona are sometimes included despite the fact that neither of these states actually border the Pacific. This is primarily because of strong ties that each state and their respective metropolitan areas have to neighboring California. The division is one of two that are located within the United States Census Bureau's Western region; the other such division is the Mountain States.

Despite being slotted into the same region by the Census Bureaua, the Pacifice and Mountain divisions are vastly different from one another in many vital respects, most notably in the arena of politics; while nearly all of the Mountain states are regarded as being conservative "red states", all of the Pacific states except Alaska are clearly counted among the liberal "blue states." Indeed, the other division with which residents of the Pacific States are seen as most closely self-identifying is New England, where many of the Pacific States' seminal settlers actually hailed from: Portland, Oregon was named after Portland, Maine, and according to the 1980s-era bestseller Dress For Success, businessmen in San Francisco display virtually identical sartorial preferences as their counterparts in Boston.