Rt. Hon. James "Jim" Griffiths (1890-1975) was a Welsh Labour politician, the prime mover in the establishment of the Welsh Office.

Griffiths was born in Ammanford, Carmarthenshire, a strongly Welsh-speaking area. He became a miner, then attended the National Labour College in London. He went into politics via the trade union movement, having become in 1924 the miners' agent in the South Wales Miners' Federation, of which he would later be President. In a by-election in 1936, he was elected MP for Llanelli, a constituency which he held until his retirement in 1970.

After Labour's 1945 election victory, Griffiths became Minister of National Insurance and a Privy Counsellor, then entered the Cabinet as Secretary of State for the Colonies in 1950.

A political moderate, he nevertheless had nationalist sympathies, and recognised the need for a measure of self-government for Wales. In 1964, under Harold Wilson's premiership, he became the first Secretary of State for Wales, and remained in the office for two years. Griffiths had a considerable popular following, and his good reputation lives after him. He was also Chairman of Labour's National Executive Committee.