Kenneth "Ken" Diaz is a special effects makeup artist, specialized in tattoo makeup, who worked as makeup artist for Tracey D'Arcy on the Star Trek: The Next Generation fifth season episode "Cost of Living" in 1992. For this work he won an Emmy Award in 1992 in the category Outstanding Individual Achievement in Makeup for a Series which he shared with Michael WestmoreGerald QuistRon WaltersJane HaymoreBob ScribnerKaren WesterfieldRichard Snell, and Tania McComas. Diaz previously worked as makeup artist for Mark Thompson on the fourth season episode "Identity Crisis".

Diaz previously won an Emmy Award in 1990 in the category Outstanding Achievement in Makeup for a Series for his work on the Alien Nation episode "Chains of Love" which he shared with Rick Stratton, Richard Snell, and Katalin Elek. Diaz received three more Emmy Award nominations: 1991 in the category Outstanding Achievement in Makeup for a Series for his work on the L.A. Law episode "God Rest Ye Murray Gentleman", shared with Thomas R. Burman and Bari Dreiband-Burman; 2004 in the category Outstanding Makeup for a Miniseries, Movie or a Special (Non-Prosthetic) for his work on the American Family episode "Journey of Dreams"; and 2010 in the category Outstanding Makeup for a Multi-Camera Series or Special (Non-prosthetic) for his work on The Big Bang Theory episode "The Electric Can Opener Fluctuation". Diaz received two Academy Award nominations in the category Best Makeup; one in 1990 for the drama Dad, shared with Greg Nelson, and the other one in 1995 for the drama My Family.


Other awards Diaz received throughout his career include a Golden Eagle Award for Outstanding Achievement Behind the Camera - Make Up at the Nosotros Golden Eagle Awards in 1997, an ALMA Award for Excellence in Make-Up in Television and Film for his work on the crime thriller Training Day in 2002, two Hollywood Makeup Artist and Hair Stylist Guild Award nominations in 2003 for Best Character Makeup - Feature for the thriller Red Dragon and for Best Period Makeup - Television Series for his work on the television series American Family, and a Hollywood Makeup Artist and Hair Stylist Guild Award for Best Period Makeup - Feature in 2004 for his work on the fantasy blockbuster Pirates of the Caribbean: The Curse of the Black Pearl, shared with Ve NeillJoel HarlowDavid DeLeon, and David Dupuis.

His celebrity clients include Crispin Glover (1991 The Doors), Harvey Keitel (1991 Bugsy), Mickey Rourke (1994 F.T.W., 1995 Fall Time, and 2011 Immortals), Jon Voight (1995 Heat, 1997 Anaconda, and 1997 U-Turn), Val Kilmer (1995 Heatand 2002 The Salton Sea), Robert Duvall (2009 Get Low), Sissy Spacek (2009 Get Low), Jeff Bridges (2009 The Man Who Stare at Goats), Nick Chinlund (2005 The Legend of Zorro), Mackenzie Crook (2003 Pirates of the Caribbean: The Curse of the Black Pearl), Ralph Fiennes (2002 Red Dragon), Ethan Hawke (2001 Training Day), Raymond Cruz (2001 Training Day), Robert DeNiro (2000 The Adventures of Rocky & Bullwinkle), Derek Mears (1999 Wild Wild West), Antonio Banderas (1998 The Mask of Zorro), Catherine Zeta-Jones (1998 The Mask of Zorro), Robin Williams (1996 Jack), Rainelle Saunders (1995 Heat), Joe Pesci (1995 Casino), Jenny Gago (1995 My Family), Christopher Lloyd (1991 The Addams Family), Jason Patric (1990 After Dark, My Sweet), Jack Lemmon (1989 Dad), Olympia Dukakis (1989 Dad), and Mel Brooks (1987 Spaceballs).

Amongs his credits as makeup artist are the drama Heaven's Gate (1989), the television comedy The Munsters' Revenge (1981, with Michael F. Blake), the science fiction film The Thing (1982), the horror film Fright Night (1985, with Rick Stratton), the fantasy film Legend (1985), the fantasy film Big Trouble in Little China (1986, starring Kim Cattrall), the comedy Greedy (1994), the television science fiction film Alien Nation: Dark Horizon (1994, with Zoltan ElekEdouard F. HenriquesJanna PhillipsCraig Reardon, Richard Snell, Rick Stratton, and Danny Valencia), the thriller Most Wanted(1997), the comic adaptation Blade (1998), the drama Erin Brockovich (2000), the Pirates of the Caribbean trilogy (2003, 2006, and 2007), the sequel Indiana Jones and the Kingdom of the Crystal Skull (2008), and the action thriller The Expendables (2010).

More recently, Diaz worked as makeup department head on the sport drama Seven Days in Utopia (2011), the drama K-11 (2012, with Audrey L. Anzures), the crime drama The Wettest County (2012, starring Tom Hardy), and the thriller Out of the Furnace (2014, starring Zoe Saldana). He is also working as prosthetic makeup artist on Sam Raimi's fantasy film Oz: The Great and Powerful (2013).