Melchior Hubert Paul Gustav Graf von Hatzfeldt zu Trachenberg (8 October 1831 – 22 November 1901) was a German diplomat who served as ambassador to Constantinople in 1878-1881, as foreign secretary and head of the Foreign Office in 1881-1885, and as ambassador to London in 1885-1901, during which time he is best known for signing the Yantze Agreement in 1900. He was once described by Otto von Bismarck as "das beste Pferd im diplomatischen Stall" – the best horse in the diplomatic stable.
A member of the House of Hatzfeld, he was born in Düsseldorf, the son of Sophie von Hatzfeldt, and died in London.