Þorsteinn Bachmann (born 25 October 1965) is an Icelandic actor. He is known for his role as Móri in Life in a Fishbowl. In 2015 he won an Edda Award for that same role.

Bachmann grew up in the Fossvogur area of Reykjavík, Iceland before moving to Breiðholt when he was 10 years old. He did not do well in school in the early years. Looking back he remembers, that he was barely able to read or write before changing schools from Fossvogur to the one in Breiðholt.

Bachmann graduated from the Icelandic Drama School in 1991. Since graduation he has worked with theatre groups in Reykjavík and Akureyri and was president of the latter for a few years. He has held many acting courses, and has served as a teacher at both the Icelandic Drama School and the Icelandic Film School. In 2013 he worked with the National Theatre of Iceland.

Before every premiere Bachmann goes to the gym, goes swimming and finishes off with a sauna. "This is something I've always done and goes with every film or stage premiere".

2005: Georg - Strákarnir okkar
2006: Steini - Blóðbönd
2010: Gummi Gumm - Gauragangur
2011: Ari - Eldfjall
2010: Benedikt - Órói
2011: Toni Group - Rokland
2011: Vörubílstjóri - Á annan veg
2002: Dagur - Maður eins og ég
2013: Prime minister - XL
2013: Police Sergeant - Falskur Fugl
2014: Móri - Vonarstræti
2014: Eiríkur - Afinn
2007: Keli - Veðramót
2001: Geiri - Íslenski draumurinn
2016: Ragnar - Eiðurinn
2018: Konrad - Under The Tree
2018: Hannes - Lof mér að falla
2018: Hörður - Andið eðlilega

2008: Ríkið
2007: Gestur - Cover Story
2015: Sigurður - Trapped
2015: Högni - Case