The City of Williamsport was established and is governed by the provisions of the Optional Third Class City Charter Law under a “strong mayor” form of government. The mayor is the chief executive and administrative official and a city council, comprised of seven members who are elected at large, constitute the legislative branch. The mayor is primarily responsible for the proper administration of the city, creates the budget and serves for a term of four years. City Council is primarily responsible for legislation and approving contracts, with each member serving a staggered term of four years.

The affairs of city government are administered at the discretion of the mayor, through the fire and police departments, and the departments of administration, code enforcement, recreation and parks, and community development . Department heads and the chiefs of the fire and police departments are appointed by the mayor. The legal affairs of the city are overseen by the city solicitor.

The needs of the city are also served by the treasurer and controller, both of whom are elected officials and serve four year terms. The primary responsibility of the city treasurer is to collect taxes and related revenues. The duty of the city controller is to ensure that all public expenditures are legitimate and warranted. Both serve as the checks and balances for the city.