Villains

No good episode of Columbo would be complete without a good antagonist for the detective to play off of.

Pilots

Episode	Villain	Portrayed by	Victim
Prescription: Murder	Dr. Ray Fleming	Gene Barry	Carol Flemming
Ransom for a Dead Man	Leslie Williams	Lee Grant	Paul Williams

The following characters appear as villains who did not actually commit murder;

Katherine Howard plays Joan Hudson, an aspiring actress who acts as Dr. Flemming's accomplice in Prescription: Murder.

Episode	Villain	Portrayed by	Victim(s)
Murder by the Book	Ken Franklin	Jack Cassidy	Jim Ferris, Lily La Sanka
Death Lends a Hand	Carl Brimmer	Robert Culp	Lenore Kennicutt
Dead Weight	Major General Martin Hollister	Eddie Albert	Colonel Roger Dutton
Suitable for Framing	Dale Kingston	Ross Martin	Rudy Matthews, Tracy O'Connor
Lady in Waiting	Beth Chadwick	Susan Clark	Bryce Chadwick
Short Fuse	Roger Stanford	Roddy McDowall	David "D.L." Buckner, Quincy
Blueprint for Murder	Elliot Markham	Patrick O'Neal	Beau Williamson

The following characters appear as villains who did not actually commit murder;

Barbara Colby plays Lily La Sanka, a woman who becomes aware that Ken Franklin is a killer, but chooses to blackmail him into a relationship rather than turn him over the police in Murder by the Book.
Rosanna Huffman plays Tracy O'Connor, an aspiring artist who acts as Kingston's accomplice in Suitable for Framing.

Episode	Villain(s)	Portrayed by	Victim
Étude in Black	Alex Benedict	John Cassavetes	Jennifer Welles
The Greenhouse Jungle	Jarvis Goodland	Ray Milland	Tony Goodland
The Most Crucial Game	Paul Hanlon	Robert Culp	Eric Wagner
Dagger of the Mind	Nicholas Frame and Lillian Stanhope	Richard Baseheart and Honor Blackman	Sir Roger Haversham, Tanner
Requiem for a Falling Star	Nora Chandler	Anne Baxter	Jean Davis (and Al Cumberland, historically)
A Stitch in Crime	Dr. Barry Mayfield	Leonard Nimoy	Sharon Marshall, Harry Alexander
The Most Dangerous Match	Emmett Clayton	Laurence Harvey	Tomlin Dudek
Double Shock	Dexter and Norman Paris	Martin Landau	Clifford Paris, Lisa Chambers

The following characters appear as villains who did not actually commit murder;

Wilfrid Hyde-White plays Tanner, an English butler who who attempts to blackmail Frame and Stanhope with his knwoledge of their crimes in Dagger of the Mind.
Mel Ferrer plays Jerry Parks, a gossip columnist and blackmailer who threatens Nora Chandler with scandal in Requiem for a Falling Star.
Tim O'Connor plays Michael Hathaway, an unscrupulous lawyer who tries to blackmail the Paris brothers into keeping him employed in Double Shock.

Episode	Villain(s)	Portrayed by	Victim(s)
Lovely But Lethal	Viveca Scott	Vera Miles	Karl Lessing, Shirley Blaine
Any Old Port in a Storm	Adrian Carsini	Donald Pleasence	Rick Carsini
Candidate for Crime	Nelson Hayward	Jackie Cooper	Harry Stone
Double Exposure	Dr. Bart Keppel	Robert Culp	Vic Norris, Roger White
Publish or Perish	Eddie Kane, hired by Riley Greenleaf	Jack Cassidy	Alan Mallory, Eddie Kane (respectively)
Mind Over Mayhem	Dr. Marshall Cahill	José Ferrer	Dr. Howard Nicholson
Swan Song	Tommy Brown	Johnny Cash	Edna Basket Brown, Tina
A Friend in Deed	Commissioner Mark Halperin and Hugh Caldwell	Richard Kiley and Michael McGuire	Margaret Halperin, Janice Caldwell (respectively)

The following characters appear as villains who did not actually commit murder;

Martin Sheen plays Karl Lessing and San Barbara Allen plays Shirley Blaine, two blackmailers who attempt to extort Viveca Scott in one way or another, only for both of them to end up dead in Lovely But Lethal.
Val Avery plays cat burglar Artie Jessup in A Friend in Deed.

Episode	Villain(s)	Portrayed by	Victim(s)
An Excercise in Fatality	Milo Janus	Robert Conrad	Gene Stafford
Negative Reaction	Paul Galesko	Dick Van Dyke	Frances Galesko, Alvin Deschler
By Dawn's Early Light	Colonel Lyle C. Rumford	Patrick McGoohan	William Haynes
Troubled Waters	Hayden Danzinger	Robert Vaughn	Rosanna Wells
Playback	Harold Van Wick	Oskar Werner	Margaret Midas
A Deadly State of Mind	Dr. Mark Collier	George Hamilton	Carl and Nadia Donner

The following characters appear as villains who did not actually commit murder;

Lesley Ann Warreb plays Nadia Donner, Dr. Collier's lover who assists him in covering up the murder of her husband in A Deadly State of Mind.

Episode	Villain(s)	Portrayed by	Victim(s)
Forgotten Lady	Grace Wheeler	Janet Leigh	Dr. Henry Willis
A Case of Immunity	Hassan Sallah	Héctor Elizondo	Youseff Alafa, Rachman Habib
Identity Crisis	Nelson Brenner	Patrick McGoohan	Geronimo
A Matter of Honor	Luis Montoya	Ricardo Montalban	Hector Rangel
Now You See Him	The Great Santini	Jack Cassidy	Jesse Jerome
Last Salute to the Commodore	Swanny Swanson	Fred Draper	Commodore Otis Swanson, Charles Clay

The following characters appear as villains who did not actually commit murder;

Sal Mineo plays Rachman Habib, who is manipulated by Sallah into becoming his accomplice in A Case of Immunity.
Robert Vaughn plays Charles Clay, an opportunist who tries to cover up the Commodore's murder in Last Salute to the Commodore in order to benefit from his death.

Episode	Villain(s)	Portrayed by	Victim(s)
Fade In to Murder	Ward Fowler	William Shatner	Claire Daly
Old Fashioned Murder	Ruth Lytton	Joyce Van Patten	Milton Schaeffer, Edward Lytton
The Bye-Bye Sky High I.Q. Murder Case	Oliver Brandt	Theodore Bikel	Bertie Hastings

Episode	Villain(s)	Portrayed by	Victim(s)
Try and Catch Me	Abigail Mitchell	Ruth Gordon	Edmund Galvin
Murder Under Glass	Paul Gerard	Louis Jourdan	Vittorio Rossi
Make Me a Perfect Murder	Kay Freestone	Trish Van Devere	Mark McAndrews
How to Dial a Murder	Dr. Eric Mason	Nicol Williamson	Dr. Charlie Hunter
The Conspirators	Joe Devlin	Clive Revill	Vincent Pauley

The following characters appear as villains who did not actually commit murder;

Jeanette Nolan, Bernard Behrens and Michael Horton play Kate O'Connell, Geroge O'Connell and Kerry Malone respectively, Joe Devlin's co-conspirators who use funds from the Friends of Northern Ireland charity to fund the terrorist activies of the Irish Republican Army.