The name "Hitler" simply means "smallholder," which refers to the land holdings of a peasant farmer. So the use of Hitler as a family name is by no means unique toa particular geographical location or to one family. As to the ancestors of Adolf Hitler, they are the first recorded in the early fifteenth century in a region of Austria known as the Waldviertel (or "wooded quarter"), which lies in the district of Weitra. There we find a deed drawn up by the Abbot of the Herzogenburg monastery dated 12 May 1436 granting Hanns and Anna Hydler some property in Raabs on the Thaya river, for which they paid forty pounds in the currency of Vienna. This record is followed by another in 1457 for a Hans Hytler who was a resident of Refing. In the following generations the "Hitler" name appears in various records: Peter and Agnes Hydler in 1465; Matheus Huetler (or Hietler, Huetler), living in Rothfahrn in 1568; Simon and Matheus Hietler (or Huetler, Huttler), living in Lempach in 1571; Baldin Huettler, living in Engelstein in 1585; Beit and Barbara Huetler, who were living in Schofberg in the late 1590's; and Stephan Hiedler (or Huetler, Hietler), who was living in Grob-Wolfgers in 1627.
The first thin one will notice in the above is the different spellings of the Hitler surname. Contrary to suggestions of some, there is nothing odd about this. Anyone who has undertaken genealogical research in Europe, the British Isles or America will know that until recent times the spelling of both personal and family names was not fixed. So researching any family name over several generations will usually yield a variety of spellings. This is why throughout the Hitler "family tree" one will find various spellings for the surname, although the pronunciations in each case is almost indistinguishable from that of the "Hitler" spelling.
Source: The Untold Story of the Hitler Family by Alfred Konder