The post of Secretary of State for Wales came into existence in October of 1964, the first incumbent being Jim Griffiths, MP for Llanelli. The position entailed responsibility for the 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 departmentss were united in a newly created Welsh Office with the Secretary of State for Wales at its head.

During the 1980s and 1990s, as the number of Conservative MPs for Welsh constituencies dwindled almost to nothing, the office fell into disrepute. Nicholas Edwards, MP for Pembrokeshire, held the post for some years, but was constantly mocked for his upper-class appearance and accent. On his departure, the government ceased to look within Wales for the Secretary of State, and the post was increasingly used as a way of getting junior high-fliers into the Cabinet. John Redwood in particular caused embarrassment to the government when he publicly demonstrated an inability to sing (or even successfully mime) the Welsh national anthem.

The introduction of the Welsh Assembly and its Cabinet following the devolution referendum of 1997 was the beginning of a new era. On 1 July 1999 the majority of the functions of the Welsh Office transferred to the new assembly. The Welsh Office was disbanded but the post of Secretary of State for Wales was retained, as the head of the newly created Wales Office.

List of Secretaries of State for Wales