Sandison was born in Haltwhistle, Northumberland and grew up in Wick, Caithness. Sandison was always interested in computing; at the age of 12, he taught himself to code on his computer. He went on to study art (at the Glasgow School of Art) from 1987–1993 and briefly taught there after graduating. In 1995 Sandison moved to Finland and now resides permanently in Tampere.
During the early 1990s Sandison exhibited alongside Young British Artists in such shows as; Wonderful Life, Lisson Gallery, London (1993) and Institute of Cultural Anxiety: Works from the Collection Institute of Contemporary Arts, London (1994).
During a 5 year hiatus in which Sandison moved away from the United Kingdom and occupied the position of Head of Fine Art at Tampere School of Art and Media. He came to wider recognition in 2001 after exhibiting in the Venice Biennale.
In 2004 Sandison became a visiting professor at Le Fresnoy, Lille. In 2010 Sandison was awarded the Ars Fennica prize by President of Finland Tarja Halonen.
Much of Sandison's work involves computer generated video projections that create immersive data installations, placing the viewer at the centre of a changing universe of words, signs, and characters. Sandison's art works to incorporate the viewer into the piece, so that the computer and human mind can work together. Sandison draws inspiration from nature and his surroundings, and attempts to capture elements of human life and the current world that we live in.
He stated in a private interview, "I don't try to make a copy or representation of something and I don't make objects. I try to create something that has its own life”. The importance of location in his work has led to projections in the Paris Catacombs, and the Forum Romano.
"Mr. Sandison's works are not compelling in traditional visual ways, but they are philosophically intriguing. You can imagine some more highly evolved version of what he does as a primary art form in some sci-fi world of the future." (Hello World, Art In Review, New York Times, Johnson, Ken. July 15th, 2005)