The Queen is head of the Commonwealth, a voluntary association of 54 independent countries. Fifteen Commonwealth realms, as well as the UK, have the Queen as their monarch. The Queen plays an important symbolic and unifying role in helping to build good collaborative relationships between Commonwealth countries.

The Commonwealth Parliamentary Conference is held annually by the Commonwealth Parliamentary Association. Its conference in September 1961 was opened by the Queen in Westminster Hall. Two months later, in November 1961, the Queen paid an important state visit to Ghana, a Commonwealth member which had become independent only in 1957.