The Secretary of State for Wales is the head of the Wales Office within the United Kingdom cabinet. He is responsible for ensuring Welsh interests are taken into account by the government, representing the government within Wales and overseeing the passing of legislation which is only for Wales. The Labour party proposed the creation of a Welsh Office run by a Secretary of State for Wales in their manifesto for the 1959 general election and once they came to power in 1964 this could be put into effect.

The post of Secretary of State for Wales came into existence on the 17 October 1964, the first incumbent being Jim Griffiths, MP for Llanelli. The position entailed responsibility for Wales and expenditure on certain public services was delegated from Westminster. In April of 1965 administration of Welsh affairs, which had previously been divided between a number of government departments were united in a newly created Welsh Office with the Secretary of State for Wales at its head. As a result the Welsh Secretary came to have responsibility for education and training, health, trade and industry, environment, transport and agriculture within Wales.

The current Secretary of State for Wales is Roland Knightly.