Captain James Hook is the main antagonist of J. M. Barrie's 1904 play Peter Pan; or, The Boy Who Wouldn't Grow Up and its various adaptations, in which he is Peter Pan's archenemy. The character is a pirate captain of the brig Jolly Roger. His two principal fears are the sight of his own blood (supposedly an unnatural colour) and the crocodile who pursues him after having previously eaten Captain Hook's hand cut off by Pan. An iron hook that replaced his severed hand has given the pirate his name.

Hook did not appear in early drafts of the play, wherein the capricious and coercive Peter Pan was closest to a "villain", but was created for a front-cloth scene (a cloth flown well downstage in front of which short scenes are played while big scene changes are "silently" carried out upstage) depicting the children's journey home. Later, Barrie expanded the scene, on the premise that children were fascinated by pirates, and expanded the role of the captain as the play developed. The character was originally cast to be played by Dorothea Baird, the actress playing Mary Darling, but Gerald du Maurier, already playing George Darling (and the brother of Sylvia Llewelyn Davies), persuaded Barrie to let him take the additional role instead, a casting tradition since replicated in many stage and film productions of the Peter Pan story.

According to A. N. Wilson, Barrie "openly acknowledged Hook and his obsession with the crocodile was an English version of Ahab", and there are other borrowings from Melville.

Barrie states in the novel: "Hook was not his true name. To reveal who he really was would even at this date set the country in a blaze." He is said to be "Blackbeard's bo'sun" and "the only man of whom Barbecue was afraid". (In Robert Louis Stevenson's Treasure Island, one of the names Long John Silver goes by is Barbecue.)

In the play, it is implied that Hook attended Eton College and Balliol College, Oxford, and his final words are "Floreat Etona", Eton's motto. In the novel, Hook's last words are a similarly upper-class "bad form", in disapproval of the way Peter Pan beats him by throwing him overboard. He also has a yellow blood disorder.

The book relates that Peter Pan began the ongoing rivalry between them by feeding the pirate's hand to a crocodile. After getting a taste of Hook, the crocodile pursues him relentlessly, but the ticking clock it has also swallowed warns Hook of its presence.

Hook is described as "cadaverous" and "blackavised", with "eyes which were of the blue of the forget-me-not" ("save when he was plunging his hook into you, at which time two red spots appeared in them and lit them up horribly") and long dark curls resembling "black candles". He is a very skilled swordsman. In many pantomime performances of Peter Pan, Hook's hair is a wig and is accompanied by thick bushy eyebrows and moustache. The hook is fixed to his right hand (often changed to the left hand in film adaptations) and is used as a weapon. He is also described as having a "handsome countenance" and an "elegance of ... diction" – "even when he [is] swearing". Barrie describes "an attire associated with the name of Charles II, having heard it said in some earlier period of his career that he bore a strange resemblance to the ill-fated Stuarts". Hook's cigar holder enables him to smoke two cigars at once. Barrie also stated in "Captain Hook at Eton" that he was, "in a word, the handsomest man I have ever seen, though, at the same time, perhaps slightly disgusting". Although Hook is callous and bloodthirsty, it makes it clear that these qualities make him a magnificent pirate and "not wholly unheroic".

In the animated film Peter Pan (1953), Captain Hook is a far more comical villain than the original character: he is seen as a vain and dastardly coward with a childish temper who is prone to crying out in terror. During the film's early development, the story department analysed Hook's character as "a fop... Yet very mean, to the point of being murderous. This combination of traits should cause plenty of amusement whenever he talks or acts".