According to the provisions of the Hessian Municipal Code (HGO), a city acts through two bodies: the municipal council (StaVo) and the magistrate. The municipal council is the supreme body of the city. It makes the important decisions and oversees the entire administration.

In Wiesbaden, 81 city councillors are directly elected by the citizens for a five-year term. They work in an honorary capacity. Anyone who is German or an EU citizen, has reached the age of 18 and has lived in Wiesbaden for at least three months can take part in the local elections. Anyone who is eligible to vote in the local elections and has lived in Wiesbaden for at least six months can be elected. Elections are held on the basis of nominations submitted by parties and voter groups. The city council elects the full-time and honorary city councillors. This does not include the Lord Mayor, who is directly elected by the citizens. The meetings of the City Council are generally open to the public.

The Chairman of the City Council, who is a member of the City Council, draws up the agenda and chairs the meeting. He or she must exercise the office neutrally and may not favor or disadvantage either a parliamentary group or a city councillor. In addition, he assumes numerous representational duties. According to parliamentary custom, the largest parliamentary group appoints the Chairman of the City Council.

The municipal council regularly forms committees to provide expert advice on the decisions of the plenary session. The municipal council determines the tasks, number of members and composition of the committees within the scope of its organizational discretion; a finance committee must be formed. The municipal council may assign certain (types of) matters to a committee for final resolution. Committees also generally meet in public.

City councillors can - and usually do - join together to form a parliamentary group. It must consist of at least two city councillors; the rules of procedure regulate the details. In Wiesbaden, the minimum size of a parliamentary group is currently three city councillors (as of 2014). The parliamentary groups are granted funding from the municipal budget to cover their personnel and material expenses.