Thórhallsson or Þórhallsson is a surname. Notable people with the surname include:
Baldur Thorhallsson (born 1968), Professor at the University of Iceland Dagur Dan Þórhallsson (born 2000), Icelandic football midfielder Höskuldur Þórhallsson (born 1973), Icelandic politician, former member of the Althing Magnús Þórhallsson, Icelandic priest and scribe Ragnar Þórhallsson (born 1987), Icelandic musician Thorlac Thorhallsson (Saint Thorlak) (1133–1193), the patron saint of Iceland Throstur Thorhallsson (born 1969), Icelandic chess grandmaster Tryggvi Þórhallsson (1889–1935), prime minister of Iceland 1927–1932