He is also known for his role in the radio duo Tvíhöfði with Jón Gnarr and for his part in the popular Icelandic television sketch comedy Fóstbræður.
[2] Between 1988 and 1994, he was active in the Icelandic music scene as vocalist and lead guitarist in the metal band HAM.
[1] In 2012, Sigurjón joined Icelandic director Baltasar Kormákur in rebranding his company under the name of RVK Studios, where he served as Head of Development until the end of 2021.
He served as showrunner of the first two seasons of Trapped and Netflix' Katla, co-created by Kjartansson and Kormákur.
In 2022 he formed his own production company, S800 and wrote and directed his first feature film, Grand finale, which premiered in 2024.