Marblehead has a population of 20,441 (2020 census). It is governed by an Open Town Meeting and a Select Board with 5 members. The Select Board Office includes the Town Administrator and is responsible for overseeing the day-to-day operation of town departments and appointed positions under the jurisdiction of the Select Board. The Town Administrator, who is appointed by the Select Board and who works under the direction of the Select Board, is responsible for the day-to-day operation and oversight of town departments and appointed positions under the jurisdiction of the Select Board.

With an Open Town Meeting, all registered voters of the Town are eligible to participate. Residents who attend Town Meeting, which convenes annually on the first Monday in May and continues on successive nights until all business is concluded, approve department budgets, purchases of equipment, the addition of Town personnel, changes to the Town's bylaws, the purchase and disposal of property and bond issues for large purchases or projects.

The Town Moderator presides and regulates the proceedings, decides all questions of order, and makes public declaration of all votes at the Annual Town Meeting and any Special Town Meeting which may be called. In addition, at the request of Town Meeting, the Moderator will appoint residents to special committees. The Town Moderator is elected annually.

Elected officials with 1-year terms are elected annually. Other officials are elected with staggered terms, so not all members are elected at the same time. Elected officials include:

• Select Board: 5 members, 1 year term
• Moderator: 1-year term
• Assessors: 3 members, 3 year term
• Cemetery Commission: 3 members, 3 year term
• Board of Health: 3 members, 3 year term
• Abbot Public Library Trustees: 5 members, 3 year term
• Housing Authority: 5 members (4 elected by the town and 1 appointed by the Governor), 5 year term
• Municipal Light Commission: 5 members, 3 year term
• Planning Board: 5 members, 3 year term
• Recreation and Park Commission: 5 members, 1 year term
• School Committee: 5 members, 3 year term
• Water & Sewer Commission: 5 members, 3 year term
• Town Clerk: 3 year Term