As of 2017, how many countries are there in the Commonwealth?

The Commonwealth of Nations (formerly the British Commonwealth), also known as simply the Commonwealth, is an intergovernmental organisation of 52 member states that are mostly former territories of the British Empire. The Commonwealth operates by intergovernmental consensus of the member states, organised through the Commonwealth Secretariat and non-governmental organisations, organised through the Commonwealth Foundation.

The Commonwealth dates back to the mid-20th century with the decolonisation of the British Empire through increased self-governance of its territories. It was formally constituted by the London Declaration in 1949, which established the member states as "free and equal". The symbol of this free association is Queen Elizabeth II who is the Head of the Commonwealth, but this role does not carry any power with it. While there are over 31 republics and five monarchies who have a different monarch, the Queen is the ceremonial head of state and reigning constitutional monarch of 16 members of the Commonwealth.

Member states have no legal obligation to one another. Instead, they are united by language, history, culture and their shared values of democracy, free speech, human rights, and the rule of law. These values are enshrined in the Commonwealth Charter and promoted by the quadrennial Commonwealth Games.