Sir George William Buchanan, GCB, GCMG, GCVO, PC (25 November 1854 – 20 December 1924) was a British diplomat.

Born in Copenhagen, Denmark, he was the youngest son of the diplomat Sir Andrew Buchanan, 1st Baronet and Frances, daughter of the Very Rev Edward Mellish and Elizabeth Leigh.

When the Dardanelles were guaranteed by Germany to the Ottoman Empire, Italy sent two secret documents via the British diplomatic corps from Sir Michael Rodd to Buchanan at St Petersburg.

It has been suggested that to have been secretly encouraged by the then Liberal government in London: The British Ambassador George Buchanan was only too aware of the court's 'pro-German sympathies'.

Rodzianko, in November 1916 that he found it difficult to get an audience at court, and expressed his view 'that Germany is using Alexandra Fedorovna to set the Tsar against the Allies'.

[3]Buchanan had developed a strong bond with Tsar Nicholas II and attempted to convince him that granting some constitutional reform would stave off revolution.

Knowing that there were plots to stage a palace coup to replace him, Buchanan formally requested an audience with the Tsar in the troubled early days of 1917.

If I were to see a friend walking through a wood on a dark night along a path which I knew ended in a precipice, would it not be my duty, sir, to warn him of his danger?

After the collapse of the autocracy (see Grand Duke Michael Alexandrovich of Russia), he developed close relations with the liberal Provisional Government, which was led initially by George Lvov and later by Alexander Kerensky and was formed after the February Revolution.

Buchanan had reported to London: "They are more active and better organized than any other group, and until they and the ideas which they represent are finally squashed, the country will remain a prey to anarchy and disorder.