Municipalities are the local authorities in Sweden. Like the other municipalities, Nynäshamn is responsible for areas like schools, care of elderly, childcare, libraries, street cleaning and drainage and water supply.
The municipality is governed by an organization of politicians and officials.
The Municipal Council (kommunfullmäktige) is the highest decision-making authority in the municipality of Nynäshamn, and takes decisions that concern finances, local taxes and the appointment of members of the committees. The members of the Municipal Council are elected from party-list proportional representation.
The Municipal Council appoints the Executive Committee (kommunstyrelsen). It is responsible for the overall management and coordination of the municipality. The Executive Committee is also responsible for city finances and concerns of trade and industry.
The Municipal Council is assisted in its work by four committees. They are: