The County government provides countywide services such as elections and voter registration, law enforcement, jails, vital records, property records, tax collection, public health, health care, and social services.

Some chartered cities such as Los Angeles and Inglewood provide municipal services such as police, libraries, parks and recreation, and zoning.

As a quasi-judicial body, the Board is the final venue of appeal in the local planning process, and holds public hearings on various agenda items.

"[3][4] The board members as of December 6, 2020[update] were: In addition to the board of supervisors, there are several elected officers that form the Government of Los Angeles County that are required by the California Constitution and California law and authorized under the Charter.

From 2007 to 2015, the CEO had direct supervision over 31 of the 37 departments while the other departments (Assessor, Auditor-Controller, Community Development Commission, County Counsel, District Attorney, Executive Office of the Board of Supervisors, Fire, and Sheriff) did not report to the CEO.

[6] Other tasks specifically given to the CEO include preparation and control of the annual budget in consultation with departments, providing leadership and direction for Board-sponsored initiatives and priorities, analysis and advocacy of state and federal legislation; coordinating Countywide strategic communications and cross-departmental public information (including the main County website), and managing capital projects and debt, asset, leasing and space management.

The CEO's office also administers the risk management and insurance programs, and facilitates departments addressing unincorporated area issues and international protocol issues, manages the County's employee relations program and compensation/classification systems, represents the board in labor negotiations, and monitors cable television companies operating in unincorporated areas.

Historically, the courthouses were county-owned buildings that were maintained at county expense, which created significant friction since the trial court judges, as officials of the state government, had to lobby the county board of supervisors for facility renovations and upgrades.

The Los Angeles Local Agency Formation Commission (LALAFCo) is the Local Agency Formation Commission (LAFCo) for Los Angeles County and regulates special districts within its jurisdiction.

The current charter was proposed by the Los Angeles County Board of Freeholders on September 24, 1912, ratified by the electorate on November 5, 1912, filed with the California Secretary of State on January 29, 1913, and became effective June 2, 1913.