Kjartansson is an Icelandic patronymic surname. Notable people with the surname include:
Ársæll Kjartansson (born 1945), Icelandic former football player Jón Kjartansson (1930–2004), Icelandic writer, better known as Jón frá Pálmholti Magnús Kjartansson (1919–1981), Icelandic politician and former minister Ragnar Kjartansson (disambiguation), various persons, including: Ragnar Kjartansson (sculptor) (1923–1989), Icelandic sculptor Ragnar Kjartansson (performance artist) (born 1976), Icelandic performance artist Sigurjón Kjartansson (born 1968), Icelandic comedian, writer and producer and part of the comic duo Tvíhöfði with Jón Gnarr