Walter Edward Guinness, 1st Baron Moyne (29 March 1880 - 6 November 1944) was a British politician.

Walter Edward Guinness was born in Dublin, Ireland and was the 3rd son of the 1st Earl of Iveagh.

From Eton he volunteered for service in the South African War, where he was wounded. In 1907 he was elected to Parliament as Conservative member for Bury St Edmunds, which he continued to represent until 1931. During World War I Guinness again served with distinction in the Suffolk Yeomanry in Egypt, and at Gallipoli. In 1922 he was appointed Under Secretary for War , the first of several political appointments which culminated in his term of office as Minister of Agriculture, November 1925 - June 1929.

After the Conservative defeat in 1929 he retired from office and was created Baron Moyne of Bury St Edmunds. During World War II he became Secretary of State for the Colonies and Leader of the House of Lords in 1941. In August 1942 he was appointed Deputy Minister of State in Cairo, and in January 1944 Minister Resident in the Middle East. On 6 November 1944 he was assassinated in Cairo by two members of the Jewish Stern Gang known in Hebrew as Lehi (Fighters for the Freedom of Israel) who were fighting the British government's decision to halt the entry of Jews to the British Mandate of Palestine during the Holocaust of World War II.