Lieutenant Donald "Don" Thompson, played by John Saxon, is a character who appears in A Nightmare on Elm Street and A Nightmare on Elm Street 3: Dream Warriors. A meta version of John Saxon also appears in Wes Craven's New Nightmare.
Don is the father of Nancy Thompson and Marge Thompson's ex-husband. Years before the events of the first film, he participates in the murder of Freddy Krueger when Krueger was freed on a technicality after a series of child murders. After this, he divorces Nancy's mother. When Tina Gray is murdered, Don (a lieutenant in the Springwood police department) uses his daughter as bait to capture Rod Lane, the suspected killer. After Rod's apparent suicide, Don ignores Nancy's reports about a resurrected Freddy Krueger and fails to help her; he and his daughter become estranged. Don realizes that Nancy was right about Freddy, and Rod did not kill Tina. He becomes an alcoholic, and loses his job.
In A Nightmare on Elm Street 3, Freddy resumes his attacks on children at a clinic where Nancy works. She and Dr. Neil Gordon visit Don and persuade him to reveal the location of Freddy's body so it can be properly buried, believing that this would force Freddy into the afterlife. When they uncover his body, Freddy seizes control of his skeleton. He kills Don by impaling him with the metal fin of a Cadillac. Freddy later poses as Don to trick Nancy into dropping her guard, allowing him to fatally stab her.
In the Nightmares on Elm Street comic miniseries, Don has been trapped and tortured since his death in Freddy's realm. When Freddy breaks through into the real world, he forces Don to summon and kill Nancy's spirit in exchange for freedom. Although Don shoots her, Nancy has become similar in power to Freddy. She forgives her father, and uses her powers to free him into the afterlife. Don has a cameo appearance in Wes Craven's New Nightmare. Donald Thompson is mentioned briefly in the novels A Nightmare on Elm Street: Suffer the Children and A Nightmare on Elm Street: Perchance to Dream as being the first one to start the fire that led to Freddy's death. The comic Nightmare on Elm Street: The Beginning features Don initially attempting to stop the mob after Freddy, then joining them once the killer threatens Nancy.