The mission of Portsmouth Free Public Library is to serve as an essential resource that grows with our community, enhances the quality of life of our users, supports lifelong learning, and offers access to information in a variety of ways. We provide outstanding customer service and a welcoming environment for all.  The Library shall enthusiastically promote its functions in the community, provide full access to a broad variety of materials and information, including beyond the local collection, and function with efficiency and courtesy to provide a pleasant experience.

The Board of Trustees is the governing body of Portsmouth Free Public Library. It consists of members who are elected from the Portsmouth Free Public Library Association.  The Board meets on the first Monday of each month at 7 PM.  In case of a Monday holiday, the Board will meet on the second Monday of the month.  The first Monday in May is the annual meeting.

Association membership is open to all residents of the Town of Portsmouth who are eighteen years of age and pay annual dues. The Portsmouth Town Council may appoint two Trustees. The Trustees serve without remuneration of any kind. Non Residents may join the Association but do not have voting rights.