Sigtryggur was born in Norway to Icelandic parents. He was a founding member of The Sugarcubes and has been a longtime fixture on the Icelandic punk and alternative music scene. Other bands he has played in have included Þeyr, Kukl, Emiliana Torrini, Ben Frost, Kippi Kaninus, SJS BIGBAND, Headpump, Bradley Fish and the Reptile Palace Orchestra. He has played on numerous recording with many artists, Howie B, Les Negresses Vertes, and Emiliana Torrini and Ben Frost, to name a few. He has also recorded under the name of Bogomil Font, his own crooner alter ego.
He made two records under the name of Steintryggur with Steingrímur Guðmundsson, and the also have a percussion group called Parabolur along with longtime collaborator Guðmundur Vignir Karlsson (Kippi Kaninus).
Sigtryggur also has a number of filmography-related accomplishments to his credit, including soundtracks for Rokland (Stormland) 2011, One Point O (2004) and Takedown (2000), acting as the Drummer in Monkey Drummer (2000) by English director Chris Cunningham, and working as a sound recordist for an episode of the documentary television series Naked Science. He has also produced "Hljómskálinn", a TV series on Icelandic music for RUV, the Icelandic national television station.
He has also written music for theater productions in Iceland, namely Enron (2010) and Chekov´s The Cherry Orchard (2011) in the Reykjavik City Theater.
From 2012 he has been the managing director for ÚTÓN / Iceland Music (formerly Iceland Music Export (IMX))