Richard Gerald Lyon-Dalberg-Acton, 4th Baron Acton (born July 30, 1941) is a British Labour politician who became Baron Acton, of Aldenham in the County of Shropshire, in 1989 upon his father's death; in 2000, he was additionally created Baron Acton of Bridgnorth, of Aldenham in the County of Shropshire (a life peerage), so that he could remain in the House of Lords.

Acton was educated at St. George's College (Zimbabwe) and at Trinity College, Cambridge, from which he emerged with a Bachelor of Arts in 1963 (later, he would receive a Master of Arts from the same institution). He served a term as director of Coutts and Company before being admitted into Inner Temple in 1976 and practising for about four years. He then served as a Senior Law Officer of the Ministry of Justice, Legal and Parliamentary Affairs of Zimbabwe from 1981 until 1985. After becoming a life peer as mentioned before, Lord Acton served on the House of Lords Constitution Committee (2001–) and on the Joint House Committee on the Consolidation of Bills (2002–).