The Thor's Hammer or Hammer of Thor is an ancient Norse symbol. In Norse mythology, Thor is the god of thunder and his hammer (called Mjölnir) has the power of lightning. During the era of Viking ascendancy, miniature Thor's Hammers were often used as religious amulets. Today, the Hammer is a major symbol for those who follow neo-Norse religions such as Asatru.
Although its traditional origins are non-racist, and although most Asatruers today are not racist, the Thor's Hammer symbol has been appropriated by neo-Nazis and other white supremacists, especially those who practice racist or white supremacist versions of neo-Norse beliefs under the guise of Odinism or Wotanism. White supremacists will often even create racist versions of the Thor's Hammer, incorporating swastikas or other hate symbols into the decoration.
Despite the widespread use of the Thor's Hammer symbol by white supremacists, the fact that it is an important symbol for non-racist Norse pagans means that one should never assume that the Thor's Hammer appearing by itself necessarily denotes racism or white supremacy. Instead, one should carefully judge the symbol in the context in which it appears.