National delegations to the Congress comprise representatives of local and regional authorities in the Council of Europe's 46 member states, as well as the partner states for local democracy. Members have either been directly elected and hold a general mandate in a local or regional authority or are politically answerable to a directly elected assembly.

Representatives and Substitutes are appointed for a five-year term in accordance with each individual member state's own procedure. Within national delegations, members are divided between the Congress' two chambers, the Chamber of Local Authorities and the Chamber of Regions.

Every delegation has to comply with the rules on fair representation:

Balanced geographical distribution of delegation members across the member state's territory;
Fair representation of the different categories of local and regional authority which exist in the member state;
Fair representation of the different political tendencies represented on local and regional authority organs;
Fair representation of women and men. Since 2008, every delegation has had to include representatives of both sexes, with at least 30% from the under-represented sex.

Delegation secretaries, special intermediaries for the Congress:

Each national delegation chooses its own secretary. Like the chairperson of the delegation, the secretary is a special intermediary for the Congress Secretariat. He or she plays a key role in information exchange, especially when national delegations come up for renewal every two years, and following local or regional elections.

Delegation secretaries also assist and advise members and act as facilitators for members participating in the work of the Congress during sessions, in committees, at conferences, in working groups, during election observation missions, etc.