Sherlock Holmes – Sherlock Holmes is the famed 221B Baker Street detective with a keen eye, acute intelligence and a logical mind. He is observant and deduction personified, and although he takes a back seat to Watson for much of this particular adventure, we always feel his presence. In the end, it takes all of his crime-solving powers to identify an ingenious killer and save the life of his next intended victim, and solve the Baskerville mystery.
Dr John Watson – The novel's narrator, Watson is Holmes' stalwart assistant at Baker Street and the chronicler of his triumphs as a private investigator. He steps into Holmes' boots for a while, expressing his eagerness to impress his colleague by cracking this most baffling of cases before Holmes returns to the fray.
Sir Hugo Baskerville – The 17th-century Baskerville who spawned the legend of the family curse. It was because of his actions and his aristocratic excesses that he meets his end by a demonic hound, then letting the shadow of death to linger on the heads of other heir of his family.
Sir Charles Baskerville – The recently deceased owner of the Baskerville estates in Devon, Sir Charles was a superstitious bachelor in waning health. His enlightened plans to invest funds in the isolated district surrounding Baskerville Hall prompt his heir, Sir Henry, to want to move there and continue his uncle's good works.
Sir Henry Baskerville – The late Sir Charles's nephew and closest known relative, Henry Baskerville inherits the baronetcy.
Dr. James Mortimer – A medical practitioner and friend of the Baskervilles. He is the executor of Sir Charles's will. Dr. Mortimer continues to assist Holmes and Watson in their twin roles as investigators and bodyguards until the conclusion of the case.
Mr. Jack Stapleton – A bookish former schoolmaster, Stapleton chases butterflies on the moors and pursues antiquarian interests. This is an alias — he is the son of Rodger Baskerville, younger brother of Sir Charles Baskerville, and he is a literal and spiritual throwback to Sir Hugo Baskerville.
Miss Beryl Stapleton – Allegedly Stapleton's sister, this dusky beauty turns out to be his wife.
Mr. & Mrs. Barrymore – The long-standing domestic servants of the Baskervilles. Mrs Barrymore and her husband harbour a dark family secret which temporarily misleads Watson about what is happening out on the moors.
Laura Lyons – The attractive daughter of a local crank who disowned her when she married against his wishes. Subsequently abandoned by her husband, she turns to Stapleton and Sir Charles Baskerville for help, with fatal consequences for the latter.
Mr. Frankland - Laura's father. Frankland is a man who likes to sue, a sort of comic relief with a chip on his shoulder about every infringement on what he sees as his rights. Villainized due to his one-time harsh treatment of Laura, Frankland is for the most part a laughable jester in the context of this story.
Selden – A dangerous criminal hiding from the police on the moors. He happened to be Mrs. Barrymore's brother and she supplied him with food and clothes. Unfortunately he gets killed by the Hound as he was dressed in Sir Henry's cloth.