Count Alexander Konstantinovich Benckendorf (Russian: Александр Константинович Бенкендорф)(1 August 1849 – 11 January 1917) was a Russian diplomat, who served as ambassador to Denmark and the United Kingdom.
He was born in 1846, the son of Count Constantin Alexander von Benckendorff and Princess Louise de Croy, and educated in France and Germany before entering the diplomatic service in 1869. He began as an attaché in Florence, and eventually served in Rome. He resigned in 1876 and lived nearly ten years on his estates, in St. Petersburg and abroad.
Returning to diplomacy in 1886, he became First Secretary at the Embassy in Vienna, and from 1897 to 1903 he was the Ambassador to Denmark. The Copenhagen post gave him a vantage point for watching the principal moving powers of European politics since the matrimonial alliances of the Danish royal family occasionally brought together in a friendly family circle the widow of Alexander III, Nicholas II and the Prince of Wales who was to become King Edward VII. In this way, Count Benckendorff received his initiation into the spirit of an Anglo-Russian rapprochement even before it actually resulted in an entente.
From 1903 until his death in 1917, he was the Ambassador to the Court of St. James's, the chief Russian diplomat in the United Kingdom. His major achievement was to organise the signing of the Anglo-Russian Entente in 1907, which solidified relations between the two nations and helped create the Triple Entente, the alignment which would later become the Allied Powers of the First World War.
He married Countess Sophie Shouvaloff in 1879, and was survived by a son and a daughter. A younger son died in one of the first battles of World War I on the East Prussian front.