The county covers about 994 square miles (2,570 km2) in the northern portion of the Central Valley, on into Gold Country.

Sacramento County extends from the low delta lands between the Sacramento River and San Joaquin River, including Suisun Bay, north to about ten miles (16 km) beyond the State Capitol and east into the foothills of the Sierra Nevada Mountains.

The southernmost portion of Sacramento County has direct access to San Francisco Bay.

Since 2010, statewide droughts in California have further strained Sacramento County's water security.

The river was named by Spanish cavalry officer Gabriel Moraga for the Santisimo Sacramento (Most Holy Sacrament), referring to the Catholic Eucharist.

Alexander Hamilton Willard, a member of the Lewis and Clark Expedition, is buried in the old Franklin Cemetery.

The highest point in the county is Carpenter Hill at 828 feet (252 m), in the southeast part of Folsom.

It is composed of the elected five-member Board of Supervisors, several other elected offices including the Sheriff, District Attorney, and Assessor, and numerous county departments and entities under the supervision of the County Executive Officer.

The Fulton- El Camino Park District Police operating under the Fulton - El Camino Recreation and Park District was disbanded as of 11/26/2024 following an alleged mismanagement of Government Funds, ethical and moral dilemmas by Emily Ballus (General Manager) and Beth Johnson (Interim Chief of Police).

[29][30] Sacramento County was politically competitive in most presidential elections between 1976 and 2004, but now votes significantly in favor of the Democratic candidates.

In gubernatorial elections, Sacramento County is typically a bellwether, having voted for the winner every time since 1962 with the exception of 1970 and 2002.

According to the California Secretary of State, as of October 22, 2012, Sacramento County has 698,899 registered voters, out of 944,243 eligible (74%).

[34] The following table includes the number of incidents reported and the rate per 1,000 persons for each type of offense.

There are also privately owned public use airports located in Elk Grove and Rio Linda.

The Sacramento County Department of Transportation (SACDOT)[39] maintains approximately 2200 miles of roadway within the unincorporated area.

In 1856, the Board of Supervisors realigned the divisions into the 14 civil townships below, plus the city of Sacramento.