Skellig was adapted into a play in 2003 directed by Trevor Nunn who thought it was important to follow the book's example of not revealing Skellig's exact nature. The play was later performed by Playbox Theatre Company in 2008. In March 2011 the play was performed at the New Victory Theater, New York by The Birmingham Stage Company who previously toured the UK with their production, from 2008 in London and Birmingham. The BSC founder and manager Neal Foster played Skellig.
Skellig has been adapted into a contemporary opera with music by American composer Tod Machover and libretto by David Almond himself. The opera was staged at The Sage Gateshead from 4 November to 19 December 2008, with orchestration by the Northern Sinfonia. The Opera starred Omar Ebrahim as Skellig with Sophie Daneman and Paul Keohone as Michael's parents.
Skellig, produced by Feel Films, was part of Sky 1's plan to invest £10 million in producing three new high-definition dramas. Filming started on 2 September 2008 in Caerphilly in Wales. Cast members included Oscar-nominee Tim Roth in the title role and Bill Milner as Michael Cooper with Skye Bennett as Mina, Kelly MacDonald and John Simm as Michael's parents (Louise 'Lou' and Steve Cooper). The film was scripted by Irena Brignull and directed by Annabel Jankel. The first showing of Skellig on Sky 1 was on 12 April 2009.