Donatus, Prince and Landgrave of Hesse (Heinrich Donatus Philipp Umberto; born 17 October 1966) is the eldest son and successor of German aristocrat Moritz, Landgrave of Hesse, and his former wife, Princess Tatiana of Sayn-Wittgenstein-Berleburg.
A great-grandson of Victor Emmanuel III of Italy, he is named in part after Georg Donatus, Hereditary Grand Duke of Hesse.
He is also a great-great-great grandson of Queen Victoria of the United Kingdom, through his paternal grandfather Philipp's mother Margaret, a granddaughter of Queen Victoria.
His father Moritz was a third cousin of Queen Elizabeth II of the United Kingdom.