The administrative departments of Snohomish County are supervised by the County Executive. Department directors are appointed by the Executive and confirmed in their positions by the County Council.

County Airport (Paine Field) serves as a general aviation, industrial, and reliever airport for the region. It provides a wide variety of aviation and industrial facilities and services, and functions as a major private-sector employment center (over 35,000 jobs), which includes Boeing's Everett plant. The airport is operated as a stand-alone enterprise fund, totally separate from other county funds, with revenues generated from real estate leases, landing fees, fuel flow charges, and runway usage charges.

Budget & Finance is responsible for managing the county's budgeting and accounting. The department also provides accounting, payroll, and other financial services for local taxing districts, such as fire, water, and sewer districts. The department is responsible for annual operating and capital budgets preparation, financial reports, economic analysis of annexations and incorporations, economic development initiatives financing, county debt management and bonding, goods and services procurements for all departments, insurance coverages, and claims and losses processing.

Corrections supervises all adult correctional institutions and programs of the county and all persons confined therein, providing safe, secure, humane and cost-effective detention in accordance with state and local law and constitutional guidelines. Facilities and programs include the county jail, work release, two minimum security facilities, electronically monitored home detention, roadside cleanup crews and a community service work program. A division of the department is responsible for determining eligibility for, and providing legally mandated attorney services for, indigent persons charged with criminal offenses.

Facilities Management provides interdepartmental support to county government in the areas of security, building maintenance, parking, property management, and facilities planning and construction.

Human Resources provides personnel services for county employees; ensures objective recruiting and selection; and supervises employee relations, safety, training, classification, compensation, benefits, and civil service administration.

Human Services develops and administers county programs to meet the shelter, health, treatment, prevention and counseling needs of low income families, domestic violence victims, substance abusers, veterans, persons who are developmentally disabled, persons who are mentally ill, children, elderly persons, and others at risk.

Information Services delivers business services to support other county departments by providing for the planning and operation of information technologies and methodologies, including data processing, Geographic Information Systems, internet services, mail center, office automation, printing, records management and telecommunications.

Medical Examiner is a physician and forensic pathologist who is authorized by state statute and county code to investigate sudden, unexpected, violent, suspicious or unnatural deaths, determining the cause and manner of death in the interest of public health, safety, and welfare.

Parks & Recreation manages the county's 8,140-acre park system; plans, acquires and develops new parks; provides recreational opportunities, including swimming, camping, picnicking, fishing, boating, golfing (Kayak Point Golf Course), youth recreation programs, and a regional trail system for biking, hiking, and equestrian recreation. The Evergreen State Fairgrounds Division promotes year-round use of the county fairground facilities located in Monroe, including the annual 12-day Evergreen State Fair. The Cooperative Extension Service, located at McCollum County Park and operated in conjunction with Washington State University, delivers programs in agriculture and natural resources, including horticulture and environmental stewardship, 4-H youth development, and family living.

Planning & Development is responsible for long range comprehensive land use planning and the permitting and inspection of building construction and land development. Planning functions include agricultural preservation; community block grant administration; ground water management; state Growth Management Act (GMA) planning; housing, resource, and transportation planning; and cultural and historic resource planning. Development services include permits for building, conditional uses, drainage, grading, mechanical, plumbing, and temporary dwellings; shoreline management and critical areas review; and zoning, rezoning, variances, platting, and code enforcement.

Public Works plans, builds and maintains roads and bridges; oversees surface water management and flood prevention in the unincorporated county; manages the county's vehicle fleet; and oversees transportation and disposal of solid wastes.