James O'Donnell

Avatars of the Mind  (New Scientist, 11 July 1998)

Silvina Ocampo

Thus Were Their Faces (trans. Daniel Balderston) (Strange Horizons, 28 March 2015)

Joseph D.Olander & Martin Harry Greenberg (eds)

Writers of the Twenty-First Century: Ursula K. Le Guin  (Vector 98, June 1980)

Lance Olsen

Tonguing the Zeitgeist  (Vector 180, August-September 1994)
[[there]]  (Big Other, 12 June 2014)
Theories of Forgetting  (Big Other, 25 June 2014)

Jerry Oltion

Abandon in Place   (Through the Dark Labyrinth, 30 September 2013)

Kenneth Oppel

Airborn   (The New York Review of Science Fiction 197, January 2005)

Rebecca Ore

Centuries Ago and Very Fast  (SF Site, Mid-August 2009)

Ada Palmer

Too Like the Lightning  (Strange Horizons, 2 September 2016)

Christine Park

Joining the Grown-Ups  (Fiction Magazine, July 1986)

John S. Partington (ed)

H.G. Wells's Fin de Siecle: Twenty First Century Reflections on the Early H.G. Wells  (Science Fiction Studies 108, July 2009)

William Paul

Mummy's Boy  (Fiction Magazine, March 1987)

David M. Peak

The Rocket's Red Glare  (Big Other, 6 August 2010)

Mervyn Peake

The Voice of the Heart: The Working of Mervyn Peake's Imagination (G. Peter Winnington)  (Science Fiction Studies 111, July 2010)

Iain Pears

Stone's Fall  (Big Other, 29 August 2010)
Arcadia  (Strange Horizons, 9 November 2015) 

John Peel

Star Trek TNG: Here There Be Dragons  (Vector 178, April-May 1994)

Julie Phillips

James Tiptree, Jr.: The Double Life of Alice B. Sheldon  (Interzone 205, August 2006, a joint review with Maureen Kincaid Speller)

Robert M. Philmus

Visions and Re-Visions: (Re)constructing Science Fiction  (Interzone 203, April 2006)

John J. Pierce

Odd Genre: A Study in Imagination and Evolution  (Vector 186, December 1995)

Jurgen Pieters

Speaking with the Dead: Explorations in Literature and History  (Journal of the Fantastic in the Arts, 2007)

Károly Pintér

The Anatomy of Utopia  (SF Site, March 2011) and (Journal of the Fantastic in the Arts Vol 22, No. 3, 2011)

Frederik Pohl

Beyond the Blue Event Horizon  (Arena SF 12, Summer 1981)
All the Lives he Led  (Strange Horizons, 22 April 2011) 

Richard Powers

Generosity  (Strange Horizons, 22 November 2010)

Tim Powers

The Anubis Gate  (Vector 124/125, April 1985)
Dinner at Deviant's Palace  (Fiction Magazine, Spring 1986)
On Stranger Tides  (Vector 267, Summer 2011) 

Terry Pratchett

A Hatful of Sky  (The New York Review of Science Fiction 197, January 2005)

Christopher Priest

The Glamour  (Vector 124/125, April 1985)
The Quiet Woman  (Vector 158, December 1990-January 1991)
Christopher Priest by Nicholas Ruddick  (Vector 158, December 1990-January 1991)
The Prestige  (Vector 185, September-October 1995)
The Glamour  (Vector 191, January-February 1997)
The Extremes  (New York Review of Science Fiction 125, January 1999
The Separation  (Vector 227, January-February 2003)
The Prestige (directed by Christopher Nolan) & The Prestige (Screenplay by Jonathan & Christopher Nolan)  (Strange Horizons, 27 November 2006)
The Magic  (Vector 258, Winter 2008)
The Islanders  (Los Angeles Review of Books, 22 April 2012) 
The Adjacent  (Vector 274, Winter 2013/14)
The Gradual  (Shadow Clarke.(22 May 2017)
An American Story (Locus 692. September 2018)

David Pringle (ed)

The Ultimate Encyclopedia of Science Fiction  (Vector 194, July-August 1997)
The Ultimate Encyclopedia of Fantasy  (Vector 205, May-June 1999)

Jeff Prucher (ed)

Brave New Words  (SF Site, Mid-July 2007)