He was born in Reykjavik, Iceland and moved to the United States at the age of 5. Gunnar lived in Maine till he was 11, his family then moving
to Texas, where he went to high school before attending the University of Texas. At the university, he did some theater work and majored in English and mathematics before going on to graduate in English and Scandinavian Studies. Despite graduating in the aforementioned fields, his first job out of high school was as a computer operator.
In the summer of 1973, he heard that
Tobe Hooper and others were in town to work on a movie and decided to try out for a part. After interviewing with Tobe Hooper and the writer of
The Texas Chain Saw Massacre (1974),
Kim Henkel, he was cast in the role of the disturbed, mentally handicapped killer, Leatherface.
After Chainsaw, Hansen went on to work as a freelance writer for magazines for several years before going on to write books, one later being set in Iceland about purported serial killer, Henry Lee Lucas. He has gone on to write multiple screenplays - one co-written with his partner
Gary Jones, director of
Mosquito (1994)).
Gunnar also directed a documentary on Greenland and had a stint designing web pages for GTE.
Death House(2017)
Ralph Stanley: An Eye for Wood(2015)
Chummy Rich: Maine Boat Builder(2012)
A Sense of Place, a Sense of Time(2001)
Butterflies & Diamonds(2015)as Kevin Morgenstern
Texas Chainsaw(2013)as Boss Sawyer, Leatherface (archive footage)
Won Ton Baby!(2009)as Dr. Kurt Severson
It Came from Trafalgar(2009)as Tex Ghoul
Dinner with Leatherface(2024)
Summer Colony(2019)
Il ritorno del maestro (Return of the Master)(2018)
Volumes of Blood: Horror Stories(2016)
Cain Hill(2016)
The History of Metal and Horror(2021)as Self
Housecore Horror: The Texas Chainsaw Massacre Turns 40(2014)as Self
Groovey.TV's Celebration of Badassery Interview Series(2009)as Self
Nash the Slash Rises Again!(2025)as Leatherface
Inner Demons(2023)as Older Man on TV Show
Death Breed(2021)as George
