A villain is an "evil" character in a story, whether a historical narrative or, especially, a work of fiction. In soap operas, the villain, sometimes called a "bad guy", is an antagonist, tending to have a negative effect on other characters. A female villain is sometimes called a villainess or "bad girl". Random House Unabridged Dictionary defines villain as "a cruelly malicious person who is involved in or devoted to wickedness or crime; scoundrel; or a character in a play, novel, or the like, who constitutes an important evil agency in the plot". An early use of the term soap opera villain was in 1942.

Tom Conroy from Media Life Magazine noted that "On soap operas, sometimes a perfectly nice regular character will suddenly turn into a villain. Viewers are rarely alerted to the change beforehand." Shelley Fralic of the Winnipeg Free Press described the "first-class villain" of soap as: "Ruthless magnate. Serial groom. Charming rogue. Unrepentant schemer. Demanding paterfamilias. Defier of death. Tough, impatient, decisive, magnetic and infuriating. The blackest of blackguards." A writer for Inside Soap magazine warned that "soap psychos" are often overly keen on their partners, keep them separated from their families, have strange things hidden in secret rooms, will attempt to kill their partner's ex-partner, and are fond of fire or high places and named a number of characters from EastEnders, Emmerdale and Coronation Street who have behaved in such ways. Debra Hale, writing about the fate of villains for the Associated Press, said that "Sometimes, a villain becomes so evil he's beyond redemption and must be killed or imprisoned", but noted that "some villains are just too delectable to kill." The following lists soap opera characters who have been described as villainous, evil, bad guys or baddies.

All My Children

Another Life

• Dan Myers
• Ron Washington

Another World

The Archers

• Hazel Woolley

As the World Turns

The Bold and the Beautiful

Brookside

Casualty

• Scott Ellison
• Tina Mollet

Coronation Street

Crossroads

• Ethan Black
• Jake Booth
• Adam Chance
• Brian Noakes
• Angel Samson

Dallas

• J. R. Ewing

Days of Our Lives

Desperate Housewives

Doctors

Dynasty

• Adam Carrington
• Alexis Colby
• Dominique Deveraux
• Sable Colby

E Street

• Mr Bad (Stephen Richardson)
• Sonny Bennett

EastEnders

The Edge of Night

• Raven Alexander Whitney

Eldorado

• Marcus Tandy

Emmerdale

Fair City

• Billy Meehan

Falcon Crest

• Angela Channing
• Joel McCarthy
• Erin Jones

Family Affairs

General Hospital

Guiding Light

High Road

• Jim Hunter
• Davie Sneddon

Holby City

• Tom Campbell-Gore
• Cameron Dunn
• Vanessa Lytton
• Isaac Mayfield
• Jac Naylor
• Kelly Yorke

Hollyoaks

Home and Away

Knots Landing

• Jill Bennett
• Abby Cunningham
• Joshua Rush
• Greg Sumner
• Danny Waleska

Loving

• Garth Slater

Neighbours

One Life to Live

Pacific Drive

• Trey Devlin

Passions

• Norma Bates
• Vincent Clarkson
• Alistair Crane
• Beth Wallace

Prisoner

• Joan Ferguson

Red Rock

• Patricia Hennesy
• Brian McGonigle

The Restless Years

• Rita Merrick

Santa Barbara

• Gina Blake Lockridge
• Keith Timmons

Search for Tomorrow

• Estelle Kendall

Shortland Street

Sunset Beach

• Eddie Connors
• Annie Douglas Richards
• Gregory Richards

Texas

• Clipper Blake

The Young and the Restless

References