A streamlined panel of 10 referees will be supported by seven dedicated assistant referees and four television match officials at rugby's showcase event.
Clancy, along with Alain Rolland, has been named in the referees panel for the tournament, while Simon McDowell has been named as an assistant referee.
Clancy, who made his refereeing debut in 2006, has taken charge of 14 Test matches to date including two games in the recent RBS 6 Nations Championship.
Rolland, who made his debut in 2001, has taken charge of 48 Test matches including the 2007 Rugby World Cup final.
The two Irishmen are joined in the referees panel by England's Dave Pearson and Wayne Barnes, France's Romain Poite, New Zealand's Bryce Lawrence, South Africa's Craig Joubert and Jonathan Kaplan, Nigel Owens of Wales and Australia's Steve Walsh.
Kaplan and Walsh will be both officiating at their fourth Rugby World Cup (a tournament record), while the referees have taken charge of 287 Tests between them at an average of 28.7 Tests per referee.
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