Zagreb County is a county in Northern Croatia. It surrounds, but does not contain, the nation's capital Zagreb, which is a separate territorial unit. For that reason, the county is often nicknamed "Zagreb ring". According to the 2011 census, the county has 317,606 inhabitants, most of whom live in smaller urban satellite towns.

The counties of Croatia are the first-level administrative subdivisions of the Republic of Croatia. Since they were re-established in 1992, Croatia has been divided into 20 counties and the capital city of Zagreb, which has the authority and legal status of both a county and a city. As of 2015, the counties are subdivided into 128 cities and 428 municipalities. The divisions have changed over time since the medieval Croatian state. They reflected territorial losses and expansions; changes in the political status of Dalmatia, Dubrovnik and Istria; and political circumstances, including the personal union and subsequent development of relations between the Kingdom of Croatia-Slavonia and the Kingdom of Hungary.