1997

Montana New Zealand Book Awards
Poetry An Anthology of New Zealand Poetry in English by Gregory O'Brien (Oxford University Press, 1997)

2001

Montana New Zealand Book Awards
History & Biography (first equal) Parihaka: The Art of Passive Resistance by Gregory O'Brien (Victoria University Press & Parihaka Pā Trustees, 2001)

2008

Montana New Zealand Book Awards
Reference & Anthology A Nest of Singing Birds: 100 Years of the New Zealand School Journal by Gregory O'Brien (Learning Media, 2007)

2013

New Zealand Post Book Awards
Illustrated Non-Fiction Pat Hanly by Gregory O'Brien (Ron Sang Publications, 2012)

2024

Ockham New Zealand Book Awards
BOOKSELLERS AOTEAROA NEW ZEALAND AWARD FOR ILLUSTRATED NON-FICTION Don Binney: Flight Path by Gregory O'Brien (Auckland University Press, 2023)

2022

Ockham New Zealand Book Awards
GENERAL NON-FICTION AWARD Voices from the New Zealand Wars | He Reo nō ngā Pakanga o Aotearoa by Vincent O'Malley (Bridget Williams Books, 2021)

1978

Goodman Fielder Wattie Book Awards
3rd The Boy, The Bridge, The River by Vincent O'Sullivan (McIndoe, 1978)

1982

New Zealand Book Awards
Fiction Dandy Edison for Lunch and Other Stories by Vincent O'Sullivan (McIndoe, 1981)

1994

Montana Book Awards
Fiction Let the River Stand by Vincent O'Sullivan (Penguin, 1993)

1999

Montana New Zealand Book Awards
Poetry Seeing You Asked by Vincent O'Sullivan (Victoria University Press, 1998)

2005

Montana New Zealand Book Awards
Poetry Nice Morning For It, Adam by Vincent O'Sullivan (Victoria University Press, 2004)

2014

New Zealand Post Book Awards
Poetry Us, Then by Vincent O'Sullivan (Victoria University Press, 2013)

2021

Ockham New Zealand Book Awards
GENERAL NON-FICTION AWARD The Dark is Light Enough: Ralph Hotere A Biographical Portrait by Vincent O'Sullivan (Penguin, Penguin Random House, 2020)

1991

Goodman Fielder Wattie Book Awards
1st The Dictionary of New Zealand Biography Volume One and Ngā Tāngata Taumata Rau, 1769–1869 by W. H. Oliver (Department of Internal Affairs & Bridget Williams Books, 1990)

1978

Goodman Fielder Wattie Book Awards
2nd John A. Lee by Erik Olssen (University of Otago Press, 1977)

1988

Goodman Fielder Wattie Book Awards
1st The Treaty of Waitangi by Claudia Orange (Allen & Unwin, & Port Nicholson Press, 1987)

1971

Goodman Fielder Wattie Book Awards
2nd Contemporary Maori Writing by Margaret Orbell (Reed, 1970)

1976

New Zealand Book Awards
Non-Fiction Traditional Songs of the Maori by Margaret Orbell (Reed, 1975)

1985

Goodman Fielder Wattie Book Awards
3rd The Natural World of the Māori by Margaret Orbell (David Bateman, 1985)

2012

New Zealand Post Book Awards
People’s Choice From Under the Overcoat by Sue Orr (Vintage, 2011)

1979

Goodman Fielder Wattie Book Awards
2nd Heinemann New Zealand Dictionary by Harry Orsman (Heinemann, 1979)

1998

Montana New Zealand Book Awards
Montana Medal for Non-Fiction The Dictionary of New Zealand English: A Dictionary of New Zealandisms on Historical Principles by Harry Orsman (Oxford University Press, 1997)

Montana New Zealand Book Awards
History & Biography The Dictionary of New Zealand English: A Dictionary of New Zealandisms on Historical Principles by Harry Orsman (Oxford University Press, 1997)