Mercer Island Library serves 25,450 residents in the City of Mercer Island. Opened in 1991, the library belongs to the King County Library System. The library system maintains 3.2 million volumes and circulates 20.9 million items per year. Mercer Island Library offers books, magazines, e-books, online resources, free Wi-Fi, public computers, two meeting rooms, one study room, copying, printing, scanning, and faxing services.