Born in Reykjavík in 1962, Sjón is the author of the novels The Blue Fox, The Whispering Muse, From the Mouth of the Whale, Moonstone, and CoDex 1962, for which he won several awards, including the Nordic Council's Literature Prize and the Icelandic Literary Prize. He has also been short-listed for the International IMPAC Dublin Literary Award and the Independent Foreign Fiction Prize, and his work has been translated into thirty-five languages.

In addition, Sjón has written more than seven poetry collections, several opera librettos, and lyrics for various artists, including Björk. He was nominated for an Oscar for his lyrics in Dancer in the Dark, and he cowrote the script of the film The Northman with its director, Robert Eggers. In 2017 he became the third writer - following Margaret Atwood and David Mitchell - to contribute to Future Library, a public artwork based in Norway spanning one hundred years.

He lives in Reykjavík, Iceland.