The novel's protagonist and in many ways its modern "knight." Marlowe is a private detective who is asked to deal with a blackmailing case for the wealthy General Sternwood. Although he is apparently attractive to women, he is not prone to take advantage of them, and he remains respectful in his own hard- boiled way. Marlowe is a man of the streets, tough and clever, but he is honest and good-willed. Other characters even call him naïve in several instances. His dialogue and manner of speaking are particularly raw and witty, often brash. A good judge of human character, he is perfect for his line of work.
The rich and very ill oil baron who has fathered two wild daughters—Vivian and Carmen Sternwood—and who has hired Marlowe as a private detective. Chandler implies that the General has fathered Carmen quite late in life and that his life has wild in its own fashion, and corrupt as well. Nevertheless, we may feel sorry for Sternwood because he seems to have a genuinely sentimental side to him. Although he is aware of his daughters' wild behavior, he is unaware of their true malice, particularly Carmen's. It is General Sternwood that introduces both plot lines—that of Geiger and that of Regan.
A pornographer who runs an illegal smut rental shop under the guise of a rare bookstore. Geiger, who is homosexual (or perhaps bisexual), blackmails General Sternwood, and murdered in the act of attempting to further his blackmail by taking nude pictures of Carmen Sternwood. Though Geiger is murdered early on in the novel, his death causes a series of events that set the plot in motion.
An ex-bootlegger and husband of Vivian Sternwood. Regan is somewhat of a phantom character: we never meet him because he is dead long before the narrative begins. He remains, however, one of the novel's main characters in the sense that much of the novel revolves around him and the search for him. General Sternwood wants Regan found because he had been a good friend to the General, sweating with him in the greenhouse many a day, providing conversation to a sick and dying man. In the end, Regan is one of the very few characters who is saved from the plight of the novel and its aftermath—he exists only in a long sleep, "the big sleep," far away from the everyday reality of a seedy Los Angeles.
The elder of General Sternwood's wild daughters. Vivian is seductive but dangerous, a beautiful and smart temptress whose dark eyes hide many secrets. She is a gambler and a drinker and an accomplice to murder. Vivian is a spoiled brat who always gets her way, and she is capable of cruelty. Nevertheless, it is possible that she has murdered her husband all to keep her father, General Sternwood, from the pain of the truth.
Vivian's younger sister. Carmen is flirtatious, wears provocative clothing (and occasionally none at all), and could be considered not only a psychotic but also a nymphomaniac. She sucks her thumb, giggles, and has a habit of repeating "You're cute" to the men who cross her path. Whether or not Carmen is a nymphomaniac, she is clearly prone to drinking, drugs, and sexual behavior, and is mentally unstable. Beneath her innocent, thumb-sucking, child-like veneer, she is the murderess of Rusty Regan.
The novel's antagonist, the thoroughly corrupt leader of a gambling racket who has at least an indirect hand in almost all the murders that take place in the novel. Though Mars is a ruthless man, he will not taint his own hands with blood; instead, he hires others to do his dirty work. He manages a hold on many of the characters in the book through his manipulative threats and offered "protection."
The Sternwoods' chauffeur, a young man. Taylor is in love with Carmen Sternwood, and tries to run away with her, but is jailed because Vivian, Carmen's sister, presses charges. The only way Taylor can see to save Carmen and her name is to murder Geiger. Not very much is known about Taylor, as his is the only death in the novel that remains ambiguous—whether he commits suicide or is killed is unclear. Because we do not know the nature of his death, we do not know how he feels about the murder he commits. Regardless, Taylor is one of the two characters in the novel—Carol Lundgren being the other—who "kill for love."
Geiger's young and handsome lover. Lundgren is both despicable and endearing: his crude, limited vocabulary annoys Marlowe while he is under his custody for killing Brody. The boy kills Brody thinking that Brody has killed Geiger, his lover. However, Lundgren honors Geiger's body in a ritualistic way, which makes us empathetic to what he may be feeling under his "tough kid" front.
A man who tries to take over Geiger's porn racket. Brody is a common criminal who blackmails and gets involved in any scheme or illegal activity that might make him a dollar. He blackmails Vivian Sternwood with the pictures of Carmen he has in his possession. He is not incredibly smart, and his life seems almost an accident, just like his death, which is a mere misunderstanding—Lundgren thinks it is Brody who has killed Geiger.
The front girl for Geiger's pornography rentals. Agnes is the equivalent of Brody: she is a common criminal, a grifter in search of a buck. She has an expensive drug addiction that has landed her in a deep hole. Agnes takes up with Brody and then with Harry Jones, both times in schemes to make an easy dollar. She is unhappy with her life, but she does nothing to better herself, instead blaming the men around her.
A man involved in crime, but for whom crime is the wrong business. Indeed, though Harry Jones is bad at criminal activity, he seems to have no other option. He is bad at tailgating, as illustrated by his poor performance in following Marlowe. He plans a moneymaking scheme with Agnes—trading his knowledge of the hiding place of Mona Grant (Eddie Mars's wife) for money—but gets killed before he ever sees the money. Harry is not very smart, but he illustrates a good will when he gives Canino the wrong address and when he protects Agnes, his partner in crime.
The local District Attorney.
The D.A.'s chief investigator. Ohls is a friend of Marlowe and tells the detective about the Sternwood job. Chandler uses Ohls and the other "cops" to illustrate a tension between "coppers" and detectives. Ohls is, generally, a good person.
A local police captain who appears to feel a rivalry with Marlowe, or perhaps with private detectives in general.
An officer at the Missing Persons Bureau who chides Marlowe for taking matters into his own hands.
The loyal and faithful wife of Eddie Mars. Though rumors abound that Mona has run off with Regan, this is not the case. Mona allows herself to be hidden in order to protect her husband, whom she does not believe or want to believe to be a crooked gambler and a ruthless murderer. Mona becomes a symbol under the name of "Silver-wig"—the name that Marlowe, who is taken by Mona, calls her.
Eddie Mars's cruel, rash, and trigger-happy gunman. Canino poisons Harry Jones with cyanide and attempts to kill Marlowe.
The Sternwoods' butler.