John Karlen (born John Adam Karlewicz) was an American character actor who played multiple roles (Willie Loomis, Carl Collins, William H. Loomis, Desmond Collins, Alex Jenkins, and Kendrick Young) on the ABC serial Dark Shadows, in various episodes which aired from 1966 to 1971. Karlen also played Harvey Lacey, husband of Mary Beth Lacey (played by Tyne Daly), on the CBS crime series Cagney & Lacey (1982–88).
Frankenstein
As Otto Roget
Surf Ninjas
As Mac
MacShayne: Winner Takes All
As Waldo Church
Impulse
As Bob Russell
Trilogy of Terror
As Thomas Amman
Daughters of Darkness
As Stefan Chilton
Pennies from Heaven
As The Detective
Racing with the Moon
As Mr. Nash
Killer's Delight
As Danny
House of Dark Shadows
As Willie Loomis
Night of Dark Shadows
As Alex Jenkins
Perry Mason: The Case of the Glass Coffin
As Jake Morrison
Night of Terror
As Manning
Downpayment on Murder
As Albert
Calendar Girl, Cop, Killer? The Bambi Bembenek Story
As John Garner
The Return of Mickey Spillane's Mike Hammer
As Chapel
A Small Town in Texas
As Lenny
The Cover Girl and the Cop
As Lieutenant Wingo
Cagney & Lacey: The View Through the Glass Ceiling
As Harvey Lacey
Delancey Street: The Crisis Within
As Richard Copell
Nightmare at 43 Hillcrest
Welcome Home, Bobby
As Geffin
Native Son
As Max
Melvin Purvis G-Man
As 'Tony' Anthony Redecci
The Invasion of Carol Enders
As David Hastings
Rosie: The Rosemary Clooney Story
As Uncle George
American Dream
As Coach Ritter
Date Rape
As Joe Farrell
Hostage Flight
As DiSalvo
The Kansas City Massacre
As Sam Cowley
Nightmare on the 13th Floor
As Sgt. Madden
The Picture of Dorian Gray
As Alan Campbell
Daddy
As Mike Burnette
Express to Terror
As Quinn
The Return of Mod Squad
As Marty
The Cloning of Clifford Swimmer
The Long Days of Summer
As Duane Haley
The Last Ride of the Dalton Gang
As Charlie Powers
Roseanne: An Unauthorized Biography
As Jerry Barr
Police Story: Burnout
As Capt. Harrison
Master of Dark Shadows
As Self
Babycakes
As Al
Without Warning: Terror in the Towers
As Jack McAllister
Cagney & Lacey: The Return
As Harvey Lacey
Cagney & Lacey: Together Again
As Harvey Lacey
Cagney & Lacey: True Convictions
As Harvey Lacey
Colorado C.I.
As Kessler
Shirts/Skins
As Herbie Bush
Lou Grant
Murder, She Wrote
As Lt. Martin McGinn
The Gallant Men
Trapper John, M.D.
Starsky & Hutch
Fame
Hawaii Five-O
As Harris
All in the Family
As Leo
227
Quincy, M.E.
The Streets of San Francisco
Kaz
Naked City
As Chuck
Charlie's Angels
As Leonard Chaffey
Hill Street Blues
Mannix
Dark Shadows
As Willie Loomis
The Hardy Boys / Nancy Drew Mysteries
Kojak
As Pinky
Hallmark Hall of Fame
As Ned
The Waltons
Weekend Special
Vega$
Police Story
Sword of Justice
Snoops
As Lieutenant Sam Akers
The Sixth Sense
The Detectives
ABC Afterschool Special
As Joe Farrell
Joe Forrester
The Magician
As Jim Russell
Mad About You
As Gus Stemple
Stoney Burke
As Mickey
American Playhouse
As Reverend Walker
Barnaby Jones
As Johnny Alban
In a Child's Name
As Joe Silvano
The Mod Squad
As Johnny Wexford
The Rockford Files
As Leo
Finder of Lost Loves
As Arthur Barwell
Hunter
As Power plant worker
Cagney & Lacey
As Harvey Lacey