Richard Maximilian Lyon-Dalberg-Acton, 2nd Baron Acton, KCVO, JP, DL (7 August 1870 – 16 June 1924) was a British peer and diplomat, ultimately Britain's first Ambassador to Finland in 1919–20.

The scion of an ancient and distinguished Shropshire family,[1] Dalberg-Acton was born in Bavaria, in the then German Empire.

He was the first and only surviving son of the 1st Baron Acton, a historian and politician, and his German wife, Marie Anna Ludomilla Euphrosina Gräfin von Arco auf Valley.

[2] The 2nd Lord Acton then served as Second Secretary at successive embassies, in Vienna from August 1902;[3] then Berne, Switzerland; Madrid in 1906–07, and The Hague.

In 1911 he was promoted First Secretary, in which grade he was charge d'affaires at Darmstadt and Karlsruhe in Germany until the outbreak of the First World War in 1914.