The politics of Belgium take place in the framework of a federal, representative democratic, constitutional monarchy. The King of the Belgians is the head of state, and the prime minister of Belgium is the head of government, in a multi-party system. Executive power is exercised by the government. Federal legislative power is vested in both the government and the two chambers of parliament, the Senate and the Chamber of Representatives. The federation is made up of (language-based) communities and (territorial) regions. Philippe is the seventh and current King of the Belgians, having ascended the throne on 21 July 2013.

Since around 1970, the significant Belgian national political parties have split into distinct representations for each communities' interests, besides defense of their ideologies. These parties belong to three main political families, though all close to the centre: the right-wing Liberals, the social conservative Christian Democrats and the Socialists forming the left-wing. Other important newer parties are the Green parties and, nowadays mainly in Flanders, the nationalist and far-right parties. Politics is influenced by lobby groups, such as trade unions and employers' organizations such as the Federation of Belgian Enterprises. Majority rule is often superseded by a de facto confederal decision-making process where the minority (the French-speakers) enjoy important protections through specialty majorities (2/3 overall and majority in each of the 2 main communities). According to the V-Dem Democracy indices, Belgium was, in 2024, the 5th most electoral democratic country in the world.

The Constitution of Belgium, the primary source of law and the basis of the political system of the Country, was established on February 7, 1831. It has been changed several times, but the most relevant reforms were made in 1970 and in 1993.

In 1970, in response to a growing civil conflict between the Dutch-speaking and French-speaking communities in Brussels, the Government declared that "the unitary state, its structure and functioning as laid down by law, had become obsolete". The new constitution recognised the existence of strong communitarian and regional differences within Belgium, but sought to reconcile these differences through a diffusion of power to the communities and the regions.

In 1993, the parliament approved a constitutional package transforming Belgium into a full-fledged federal state.

The King of the Belgians is the constitutional head of the Belgian state and holds office for life. The duties of the king are laid out by the Belgian Constitution and other laws enforced under it.

As titular head of state, the king plays a ceremonial and symbolic role in the nation. His main political function is to designate a political leader to form a new cabinet after an election or the resignation of a cabinet. In conditions where there is a "constructive vote of no-confidence," the government has to resign and the lower house of Parliament proposes a new prime minister to the king. The king is also seen as playing a symbolic unifying role, representing a common national Belgian identity.

Philippe succeeded his father Albert II on 21 July 2013 upon his abdication.