King County Library System
| King County Library System | |
|---|---|
Bellevue Regional Library, the largest library in the system | |
| Location | King County, Washington, U.S. |
| Type | Public library |
| Established | 1942 |
| Branches | 49 |
| Collection | |
| Size | 3.7 million items |
| Access and use | |
| Access requirements | Residence in King County except the city of Seattle and the towns of Hunts Point and Yarrow Point |
| Circulation | 21.5 million |
| Population served | 1.6 million |
| Members | 630,566 |
| Other information | |
| Budget | $164.6 million (2025) |
| Director | Heidi Daniel |
| Employees | 842 |
| Website | kcls |
| References: Washington Public Library Statistical Report, 2023 | |
The King County Library System (KCLS) is a public library system serving most residents of King County, Washington, United States. It has 49 locations in the areas of the county around Seattle, which has a separate city library system. KCLS is headquartered in Issaquah, Washington, and was the busiest library system in the United States in 2010 with a circulation of 22.4 million items. As of 2023, the library system serves a population of 1.6 million residents and has 3.7 million items in its collection, which includes books, periodicals, audio and videotapes, films, disc media, and online resources.