Peter Pacey
- Attendant
Graham Padden
Shaker Paleja
- Operating Room Surgeon
Mimi Paley
- Young Samantha Mulder
David Palffy
- Dark Man
- Mariano Cuchillo
Oleg Palme
- Doctor
- Valet
Geoffrey Palmer
- Simon Sinclair
- Avery
Joel Palmer
- Kevin Morris
- Charlie / Michael Holvey
Jonathan Palmer
- Principal
Valentine Palmer
- News Reporter
Tony Pantages
- Lieutenant Fraser
Andy Pantelidou
- George
Clive Panto
- TV Commentator
Morris Panych
- Dr Simon Auerbach
- Grey-Haired Man
Catherine Paolone
- Ellen Kaminsky
Terry Paris
- Lucho
F William Parker
- Dr Blankenship
Monica Parker
- Ladonna
Nicole Parker
- Redheaded Chick
- Second Stoner
Robin Parkinson
- Taxi Driver
James Parks
- Agent Terry Sullivan
Richard Parmentier
- Ivan
Zahf Paroo
- Second Reporter
Cory Parravano
- Jason McPeck
Jennifer Parsons
- Nora Pearce
Joe Pascual
- Examiner
Sheila Paterson
- Gina Watkins
- Anna Fugazzi
- Louella Everage / Helena Davõs
Angela Paton
- Miriam Lukesh
Laurie Paton
- Mrs Marsden
Barbara Patrick
- Barbara Doggett
John Patrick
- Soldier
Robert Patrick
- Special Agent John Jay Doggett
- 8ABX01 Within
- 8ABX02 Without
- 8ABX03 Redrum
- 8ABX04 Patience
- 8ABX05 Roadrunners
- 8ABX06 Invocation
- 8ABX07 Via Negativa
- 8ABX08 Per Manum
- 8ABX09 Surekill
- 8ABX10 Salvage
- 8ABX11 The Gift
- 8ABX12 Badlaa
- 8ABX13 Medusa
- 8ABX14 This Is Not Happening
- 8ABX15 DeadAlive
- 8ABX16 Vienen
- 8ABX17 Empedocles
- 8ABX18 Three Words
- 8ABX19 Alone
- 8ABX20 Essence
- 8ABX21 Existence
- 9ABX01 Nothing Important Happened Today
- 9ABX02 Nothing Important Happened Today II
- 9ABX03 Dæmonicus
- 9ABX04 Hellbound
- 9ABX05 4-D
- 9ABX06 Lord Of The Flies
- 9ABX07 John Doe
- 9ABX08 Trust No 1
- 9ABX09 Underneath
- 9ABX10 Provenance
- 9ABX11 Providence
- 9ABX12 Scary Monsters
- 9ABX13 Audrey Pauley
- 9ABX14 Improbable
- 9ABX15 Jump the Shark
- 9ABX16 Release
- 9ABX17 William
- 9ABX18 Sunshine Days
- 9ABX19 / 9ABX20 The Truth
Michael Patterson
- Father
Rudi Patterson
- Herbie
Aaron Paul
- David Winkle [Sky Commander Winky]
Scott Paulin
- Jeffrey Conlon
Pamela Paulshock
- Brittany
Jade Pawluk
- Naked Lair Victim
John Payne
- Mr Dorney [Fort Maryland Cryology Department Guard]
- Jerald Glazebrook
Sandra Payne
- Phillipa
Willie Payne
- Carter
Amanda Pays
- Inspector Phoebe Green
Aaron Pearl
- Officer Tollin
Melanie Peck
Eileen Pedde
- Angie
- Mrs Skur
Amanda Peet
- ASAC Dakota Whitney
Nigel Pegram
- Wendell
Nichole Pelerine
- Sara Shipley
Mark Pellegrino
- Derwood Spinks
Ron Pember
- Jack Cobber
Charles Pemberton
- Big Man
- Jack Cobber
Peter Penry-Jones
- Cummings
Kyle Pepi
- Billy Underwood
Ryan Pepi
- Billy Underwood
Emily Perkins
- Dara Kernof / Paula Koklos / Roberta Dyer [The Nepholim]
Freda Perry
- Mrs Wright
Jane Perry
- Day Care Operator
- Dorothy Bahnsen
Morris Perry
- Radouk
Lisa Jane Persky
- Laura Weinsider
Bob Peters
- Idaho News Anchor
Clarke Peters
- President Ojuka
LuanPeters
- Lady in Sports Car
Robert Peters
- Sergeant
David Petersen
- Older John Barnett
Luvia Petersen
- OR Nurse
Michael Petrovitch
- Callinari
Valarie Pettiford
- FBI Agent
Cary Pfeffer
- Anchorman
Walter T Phelan Jr
- Alien
Win Phelps
- Director
Bobbie Phillips
- Dr Bambi Berenbaum
Grace Phillips
- Betsy Monroe
Patrick Phillips
- First Clinician
James Pickens Jr
Art Pickering
- Germ Suit Trooper
Donald Pickering
- Brigadier Tennant
Tom Pickett
- Officer
Wiley Pickett
- Second Trooper
Lisa Picotte
- Stacey Muir
DJ Pierce
Angela Piette
- First Guest
Arlene Pileggi
- Arlene [Skinner's Assistant]
- Second Agent
- First Woman Party-Goer
Mitch Pileggi
- Assistant Director Walter Sergei Skinner
- 1X20 Tooms
- 2X01 Little Green Men
- 2X02 The Host
- 2X04 Sleepless
- 2X06 Ascension
- 2X08 One Breath
- 2X16 Colony
- 2X17 End Game
- 2X22 F Emasculata
- 2X25 The Anasazi
- 3X01 The Blessing Way
- 3X02 Paper Clip
- 3X14 Grotesque
- 3X15 Piper Maru
- 3X16 Apocrypha
- 3X17 Pusher
- 3X21 Avatar
- 3X23 Wetwired
- 3X24 Talitha Cumi
- 4X01 Herrenvolk
- 4X04 Teliko
- 4X05 The Field Where I Died
- 4X08 Paper Hearts
- 4X09 Tunguska
- 4X10 Terma
- 4X11 El Mundo Gira
- 4X15 Memento Mori
- 4X16 Unrequited
- 4X18 Max
- 4X20 Small Potatoes
- 4X21 Zero Sum
- 5X02 Redux
- 5X03 Redux II
- 5X08 Kitsunegari
- 5X12 Bad Blood
- 5X14 The Red and the Black
- 5X18 The Pine Bluff Variant
- 5X19 Folie à Deux
- 5X20 The End
- The X-Files: Fight the Future
- 6ABX01 The Beginning
- 6ABX03 Triangle
- 6ABX10 SR 819
- 6ABX11 Two Fathers
- 6ABX12 One Son
- 6ABX15 Monday
- 6ABX21 Field Trip
- 6ABX22 Biogenesis
- 7ABX03 The Sixth Extinction
- 7ABX04 The Sixth Extinction II: Amor Fati
- 7ABX05 Millennium
- 7ABX10 Sein und Zeit
- 7ABX15 En Ami
- 7ABX16 Chimera
- 7ABX18 Hollywood AD
- 7ABX19 Brand X
- 7ABX21 Je Souhaite
- 7ABX22 Requiem
- 8ABX01 Within
- 8ABX02 Without
- 8ABX07 Via Negativa
- 8ABX08 Per Manum
- 8ABX11 The Gift
- 8ABX14 This Is Not Happening
- 8ABX15 DeadAlive
- 8ABX16 Vienen
- 8ABX18 Three Words
- 8ABX19 Alone
- 8ABX20 Essence
- 8ABX21 Existence
- 1AEB09 The Lying Game
- 1AEB10 Tango de los Pistoleros
- 9ABX01 Nothing Important Happened Today
- 9ABX02 Nothing Important Happened Today II
- 9ABX03 Dæmonicus
- 9ABX04 Hellbound
- 9ABX05 4-D
- 9ABX06 Lord Of The Flies
- 9ABX07 John Doe
- 9ABX08 Trust No 1
- 9ABX09 Underneath
- 9ABX10 Provenance
- 9ABX11 Providence
- 9ABX12 Scary Monsters
- 9ABX13 Audrey Pauley
- 9ABX14 Improbable
- 9ABX15 Jump the Shark
- 9ABX16 Release
- 9ABX17 William
- 9ABX18 Sunshine Days
- 9ABX19 / 9ABX20 The Truth
- The X-Files: I Want to Believe
- 1AYW01 My Struggle
- 1AYW02 Home Again
- 1AYW03 Mulder & Scully Meet the Were-Monster
- 1AYW04 Babylon
- 1AYW05 Founder's Mutation
- 1AYW06 My Struggle II
Bruce Pinard
- Perry Simon [Executioner]
Byrne Piven
- Frank Sparks
Frederick Pleasure II
- Tow Truck Driver
Gerard Plunkett
- Dr Calderon
Steve Plytas
- Second Foreign Observer
Jared Poe
- FBI Cadet Rudolph Hayes [Stuart Mimms]
Greg Poland
- Second Windbreaker Man
Vic Polizos
- Agent Frank Burst
Barbara Pollard
- Gwen
Silvio Pollio
- Emanuel Morales
Alan Polonsky
Peter Polycarpou
Kirstie Pooley
- Secretary
Kevin Porter
- Motivational Speaker
Linda Porter
- Elderly Deaf Woman
Russell Porter
- Scott Simic
Steven M Porter
- Harold Spuller
Eric Pospisil
- Young Richard
Ringo
Langly
Tom Poston
- Fred Tobalowski [Cap'n Toby]
Brian Poth
- Gabe Rotter
CCH Pounder
- Special Agent Lucy Kazdin
Michael Praed
- Terrorist
Brianne Prather
- Young Woman
George Pravda
- Hirschfield
Ernie Prentice
- Leo Kroytzer
Lawrence Pressman
- Mr Milsap
Cynthia Preston
- Nancy Aaronson
Duncan Preston
- Karl Drake
Benito Prezia
- Old Italian Man
Charlie Price
- Second Gunman
Barry Primus
- Robert Dorlund
Bryan Pringle
Valentine Pringle
- Buzz
PJ Prinsloo
- Tagger
Tim Progosh
- Mr Fliebling
John Prosky
- Medical Examiner
Roy Purcell
- Richardson
David Purdham
- Dr Lev
Theresa Puskar
- Mrs Kemper [School Teacher]
Robert Putt
- Inspector Newton
Michael Puttonen
- Motel Manager
- Dr Pilsson
- Conductor
- Martin Alpert
- Dr Bromberg
John Pyper-Ferguson
- Paul
- Detective John Kresge