Sydney Arnold, 1st Baron Arnold was a radical British Liberal Party politician who later joined the Labour Party and served as a government minister.

The first MacDonald ministry of the United Kingdom lasted from January to November 1924. The Labour Party, under Ramsay MacDonald, had failed to win the general election of December 1923, with 191 seats, although the combined Opposition tally exceeded that of the Conservative government, creating a hung parliament. Stanley Baldwin remained in office until January 1924.