The Sea-Wolf is a 1904 psychological adventure novel by American writer Jack London. The book's protagonist, Humphrey Van Weyden, is a literary critic who is a survivor of an ocean collision and who comes under the dominance of Wolf Larsen, the powerful and amoral sea captain who rescues him. Its first printing of forty thousand copies was immediately sold out before publication on the strength of London's previous The Call of the Wild. Ambrose Bierce wrote, "The great thing—and it is among the greatest of things—is that tremendous creation, Wolf Larsen... the hewing out and setting up of such a figure is enough for a man to do in one lifetime... The love element, with its absurd suppressions, and impossible proprieties, is awful."

The personal character of the novel's antagonist "Wolf" Larsen was attributed to a real sailor London had known, Captain Alex MacLean. According to London himself, "much of the Sea-Wolf is imaginary development, but the basis is Alexander McLean". Captain Alex MacLean, or McLean, was born May 15, 1858, in East Bay, Nova Scotia. He sailed mostly in the Pacific Northwest with his brother, Captain Dan MacLean. MacLean was at one time the Sheriff of Nome, Alaska. The MacLean captains maintained their ties to Cape Breton Island despite having spent much of their lives sailing the Pacific Coast. They have living descendants.

London, who was called "Wolf" by his close friends, also used a picture of a wolf on his bookplate, and named his mansion Wolf House. Given that Van Weyden's experiences in the novel bear some resemblance to experiences London had, or heard told about, when he sailed on the Sophia Sutherland, the autodidact sailor Van Weyden has been compared to the autodidact sailor Jack London.^{[citation needed]}

London's intention in writing The Sea-Wolf was "an attack on (Nietzsche's) super-man philosophy." Nietzsche and Schopenhauer are mentioned in the second sentence of the novel as the preferred reading of the friend Humphrey Van Weyden visited before his shipwreck. The novel also contains references to Herbert Spencer in chapters 8, 10, Charles Darwin in chapters 5, 6, 10, 13, Omar Khayyam in chapters 11, 17, 26, Shakespeare in chapter 5, and John Milton in chapter 26.

The plot has some initial similarities to Captains Courageous by Rudyard Kipling in that they each have an idle, rich young man rescued from the sea and shanghaied into becoming a working sailor; however, the two stories differ widely in plot and moral tone.

The Sea-Wolf tells the story of a soft, domesticated protagonist — an intellectual man named Humphrey Van Weyden — forced to become tough and self-reliant by exposure to cruelty and brutality. The story starts with him aboard a San Francisco ferry, called Martinez, which collides with another ship in the fog and sinks. He is set adrift in the Bay, eventually being picked up by Wolf Larsen. Larsen is the captain of a seal-hunting schooner, the Ghost. Brutal and cynical, yet also highly intelligent and intellectual, he rules over his ship and terrorizes the crew with the aid of his exceptionally great physical strength. Van Weyden describes him as individualist, hedonist, and materialist. Larsen does not believe in the immortality of the soul; he finds no meaning in his life save for survival and pleasure, and he has come to despise all human life and deny its value. Being interested in someone capable of intellectual disputes, he somewhat takes care of Van Weyden, whom he calls "Hump", while forcing him to become a cabin boy, do menial work, and learn to fight to protect himself from a brutal crew.

A key event in the story is an attempted mutiny against Wolf Larsen by several members of the crew. The organizers of the mutiny are Leach and Johnson. The two were motivated by previous slights by Wolf Larsen: Johnson had previously been beaten severely by Larsen, and Leach had been punched earlier while being forced to become a boat-puller. The first attempt at mutiny involved sending Larsen overboard; however, he manages to climb back onto the ship. Searching for his assailant, he ventures into the sleeping quarters, located beneath the main deck, the only exit being a ladder. Several, at least seven men, take part in the mutiny and attack Larsen. Larsen however, demonstrating his inhuman endurance and strength, manages to fight his way through the crew, climb the ladder with several men hanging off him, and escape relatively unharmed. Van Weyden is promoted as mate, for the original mate had been murdered. Larsen later gets his vengeance by torturing his crew, and constantly claiming that he is going to murder Leach and Johnson at his earliest convenience. He later allows them to be lost to the sea when they attempt to flee on a hunting boat.

During this section, the Ghost picks up another set of castaways, including a young unmarried woman named Maud Brewster. Miss Brewster and Van Weyden had known each other previously, but only as writers. Both Wolf Larsen and Van Weyden immediately feel attraction to her, due to her intelligence and "female delicacy". Van Weyden sees her as his first true love. He strives to protect her from the crew, the horrors of the sea, and Wolf Larsen. As this happens, Wolf Larsen meets his brother Death Larsen, a bitter opponent of his. Wolf kidnapped several of Death's crew and forced them into servitude to fill his own ranks, lost previously during a storm. Larsen attempts to assault Brewster, but is stopped by one of his intense, immobilizing headaches, which allows her and Van Weyden to steal a boat and flee.