2019 Dame Companion of the New Zealand Order of Merit
For services to film

2005 Grammy Awards
Best Song Written for a Motion Picture, Television, or Other Visual Media (shared with Howard Shore and Annie Lennox): for Into the West(from The Lord of the Rings: The Return of the King)

2004 Academy Awards
Best Picture: The Lord of the Rings: The Return of the King
Adapted Screenplay (shared with Peter Jackson and Philippa Boyens): for The Return of the King
Best Music - Original Song (shared with Howard Shore and Annie Lennox): for Into the West

2004 Bafta Awards
Best Film: The Lord of the Rings: The Return of the King
Adapted Screenplay (shared with Philippa Boyens and Peter Jackson): for The Return of the King
Nominated for Best Children's Film: for The Return of the King

2004 Golden Globes
Best Original Song - Motion Picture (shared with Howard Shore and Annie Lennox): Into the West

2004 Producers Guild of America Awards
Motion Picture Producer of the Year (shared with Barrie M Osborne and Peter Jackson): for The Return of the King

2004 Australian Film Institute Awards
Best Foreign Film: The Return of the King

2004 World Soundtrack Awards (Belgium) 
Nominated for Best Original Song Written for Film (with Howard Shore and Annie Lennox): Into the West

2004 Writers Guild of America
Nominated for Best Adapted Screenplay (with Philippa Boyens and Peter Jackson): for The Return of the King

2004 Australian Film Institute Awards
Best Foreign Film: The Lord of the Rings: The Two Towers

2003 Academy Awards
Nominated for Best Picture: The Two Towers

2003 Bafta Awards
Audience Award for Best Film: for The Lord of the Rings: The Two Towers
Nominated for Best Feature, and Children's Award for Best Feature: for The Lord of the Rings: The Two Towers

2003 Producers Guild of America Awards
Nominated for Motion Picture Producer of the Year (with Barrie M Osborne and Peter Jackson): for The Two Towers

2003 World Soundtrack Awards
Nominated for Best Original Song Written for a Film (with Howard Shore, Janet Roddick, David Donaldson, Steve Roche, David Long and Emiliana Torrini): Gollum's Song

2002 Member of the New Zealand Order of Merit
For services to the film industry

2002 Bafta Awards
Audience Award for Best Film of the Year: The Fellowship of the Ring
Nominated for Adapted Screenplay (with Philippa Boyens and Peter Jackson), and Best Children's Feature

2002 Australian Film Institute Awards
Best Foreign Film: The Fellowship of the Ring

2002 Academy Awards
Nominated for Best Film
Nominated for Adapted Screenplay (with Philippa Boyens and Peter Jackson: for The Fellowship of the Ring

2002 Writers Guild of America
Nominated for Adapted Screenplay (with Philippa Boyens and Peter Jackson): for The Fellowship of the Ring

2001 SPADA Screen Industry Awards (Screen Production and Development Association, New Zealand)
SPADA/OnFilm Industry Champion (shared with Peter Jackson)

1995 New Zealand Film and Television Awards
Best Screenplay (shared with Peter Jackson): for Heavenly Creatures

1995 Academy Awards
Nominated for Best Writing, Screenplay Written Directly for the Screen (with Peter Jackson): for Heavenly Creatures

1995 Writers Guild of America
Nominated for Best Screenplay Written Directly for the Screen (with Peter Jackson): for Heavenly Creatures

1993 New Zealand Film and TV Awards
Best Screenplay (shared with Stephen Sinclair and Peter Jackson): for Braindead

1990 New Zealand Film Awards
Nominated for Best Screenplay (with Peter Jackson, Stephen Sinclair and Danny Mulheron): for Meet the Feebles