Napa County is a county located north of the San Francisco Bay Area in the U.S. state of California. It is coterminous with the Napa, California, Metropolitan Statistical Area. As of the 2010 census the population is 136,484. The county seat is Napa. Napa County was one of the original counties of California, created in 1850 at the time of statehood. Parts of the county's territory were given to Lake County in 1861. The word napa is of Native American origin and has been variously translated as "grizzly bear", "house", "motherland", and "fish". Of the many explanations of the name's origin, the most plausible seems to be that it is derived from the Patwin word napo meaning house, although local residents will often cite an urban legend that gives the translation as "you will always return".

Das Napa County mit dem Napa Valley ist ein 1850 errichteter Verwaltungsbezirk (County) im US-Bundesstaat Kalifornien und liegt nördlich der San Francisco Bay Area an der Bucht von San Pablo entlang des Napa Rivers. Der Name Napa stammt von den Ureinwohnern und bedeutet vermutlich Haus.

Le comté de Napa est un comté de l'État de Californie aux États-Unis. Au recensement de 2000, il comptait 124 279 habitants. Son chef-lieu est Napa. Le comté de Napa est parmi les comtés originaux de Californie, créé en 1850 lors de la création de l'État. Une partie du territoire est cédée au comté de Lake en 1861.

Napa County är ett i den centrala delen av delstaten Kalifornien i USA. År 2000 hade Napa totalt 124 279 invånare. Den administrativa huvudorten (county seat) är Napa. Napa County grundades år 1850.´

La Contea di Napa, in inglese Napa County, è una contea dello stato della California, negli Stati Uniti. La popolazione al censimento del 2000 era di 124.279 persone. Il capoluogo di contea è Napa.