The five members of Mill Valley's Library Board of Trustees are appointed by the City Council. Trustees are appointed for a three-year term and may serve no more than two consecutive terms. Terms are staggered to minimize the impact of turnover. One trustee may reside outside the city limits within the unincorporated (county) area served by the Library.
The Library Board is considered an advisory board because it does not have responsibility for appointing the head librarian or submitting the Library's budget to the City. The Library Board is responsible for overseeing the long range planning for the Library, setting Library policy, providing necessary support for the effective operation of the Friends of the Library and Library Foundation, serving as a liaison between the Library and the City Council, as well as the general public, and, in general, undertaking those projects and programs that promote the welfare of the Library in the Community of Mill Valley.
In addition to the five appointed trustees, the Library Board includes adjunct positions which serve as liaisons to other organizations or communities with special ties to the Library: the Friends of the Mill Valley Public Library, the Mill Valley Historical Society, the Mill Valley Public Library Foundation, and a representative from Tamalpais High School.
The board's officers include a president and vice president who are elected annually. All Library Board meetings are open to the public. The Library Board meets on the second Thursday of every month at 7:00 pm in the Library's Conference Room.