The novel focuses on the young life of Duddy Kravitz, a poor Jewish boy raised in Montreal, Quebec. Family, friends, lovers and teachers all contribute to Duddy's burgeoning obsession with power and money — desires embodied in the possession of land. As a child, Duddy learns from his grandfather that "a man without land is nobody," and Duddy comes to believe land ownership to be life's ultimate goal and the means by which a man is made into a somebody.
Duddy begins to move towards this goal by working for his Uncle Benjy. Their relationship is strained: Uncle Benjy, a wealthy clothing manufacturer with socialist sympathies, has always favored Duddy's brother Lennie, who wants to become a doctor. Uncle Benjy takes a dim view of Duddy's commercial ambitions, seeing them as avaricious and crass. During the summer after high school, Duddy takes a job as a waiter at a hotel in Ste. Agathe. He stumbles upon a beautiful and secluded lake while out with his soon-to-be lover and "Girl Friday" Yvette. A born entrepreneur, Duddy immediately sees that the lake has tremendous potential as the future site of a summer resort.
Duddy returns to Montreal and starts a company to produce bar-mitzvah films. To this end he hires Friar, a blacklisted, alcoholic, avant-garde filmmaker. Since Duddy's childhood, his father, Max, had told him stories about Jerry Dingleman, the local "boy wonder" whose rags-to-riches story is canonical among the residents of St. Urbain Street. Looking for help with his film company, Duddy attempts to engage Dingleman. The two travel to New York, but Duddy fails to secure any assistance from the boy wonder who sees Duddy as a naive upstart and uses him to ferry a package of heroin across the Canada-U.S. border. On the way back from New York he does, however, meet Virgil, an amicable and trusting American with a consignment of pinball machines for sale. Back in Montreal, Duddy rents an apartment and an office for himself and Yvette and, as the plots of land around Lac Saint-Pierre go up for sale, his Laurentian land empire grows.
After Mr. Friar tries unsuccessfully to seduce the comely Yvette he wordlessly and suddenly abandons his work with Duddy. Duddy rebounds by starting a new movie distribution business and hires Virgil as a travelling projectionist. A few months later, Virgil, an epileptic (a fact known to Duddy when given the job), experiences a seizure while driving, crashes the vehicle and is subsequently paralyzed from the waist down from his injuries. Yvette, blaming Duddy for the accident, takes Virgil to Ste. Agathe where she cares for him as he recovers. Duddy is left to show the movies seven days a week while still trying to oversee movie production at the same time. Meanwhile, Uncle Benjy finds he has a terminal illness. He tries to mend fences with Duddy, but Duddy rebuffs his uncle's request that the two see each other more frequently during his final days. Uncle Benjy's death acts as a trigger for Duddy who then experiences a nervous breakdown and refuses to leave his room for a week. Having no communication with the outside world, Duddy loses his clients, and is thus forced to declare bankruptcy and to give all his possessions over to the state (except for the land, which was all in Yvette's name due to Duddy's being considered a minor).
After Duddy recovers from his nervous breakdown, he invites Yvette and Virgil to move with him into his uncle's mansion, which was left to Duddy as an inheritance on the condition that the house not be rented out or sold. When Duddy hears of the last bit of land around Lac St. Pierre going up for sale, he exhausts his few remaining contacts for money but still comes up short. Pressed for time and desperate to claim the last piece of his empire, especially knowing Dingleman has expressed interest in the land and has the money for it, Duddy resorts to forging a cheque from Virgil's chequebook to acquire the outstanding money. Yvette finds out and tells Duddy's grandfather, who is embarrassed and unhappy with the way Duddy has obtained the land. This theft also prompts Yvette and Virgil to move out of the mansion and forbid Duddy to ever see them again. The ending of the novel is ambiguous: Duddy's selfishness and ruthless materialism, which supersede his love for Yvette, are obviously negative qualities. On the other hand, Duddy's youth, impatience with snobbery, and underdog status are ameliorating factors, and his gutsy entrepreneurial creativity is admirable.
An older Duddy makes brief, comic appearances in Richler's later novels. Duddy never loses his drive to make money.
The Kravitz Family
Simcha Kravitz - Duddy's grandfather. Throughout Duddy's childhood he is close to his grandfather, and it is Simcha who sparks Duddy's drive for land ownership when he tells young Duddy that "a man without land is nobody." Duddy purchases land with his grandfather in mind, intent on giving him a farm and the best retirement his money can buy.
Benjamin & Ida Kravitz - Duddy's aunt and uncle. A childless couple with a strained relationship, Uncle Benjy takes quickly to Duddy's older brother, Lennie, providing him with funding for university. Uncle Benjy's attitude towards Duddy is markedly different, as he takes much less interest in the sly young boy's development. The family become estranged from Ida due to her winters in the southern states and her eventual divorce from Benjy, but she returns briefly upon finding out about Benjy's illness.
Max & Minnie Kravitz - Duddy's mother and father. His father, a crude simple man, makes a living by driving a taxi. His mother died when Duddy was young, and his memories of her are few. Throughout the story he pesters Lennie for information about their mother, wanting to know if his mother liked him.
Leonard (Lennie) Kravitz - Duddy's older brother by six years. Lennie attends medical school, funded by Uncle Benjy, and is set to fulfill the St. Urbain Street dream of being a lawyer or doctor. A studious boy, Lennie falls in with a crowd of well-off students during his university years who take advantage of him. When his studies plunge and are at risk as a result of his group of friends, Lennie flees to Toronto but is brought back by an insistent Duddy.
Dudley(Duddy)(Duddel) Kravitz - As a youth, Duddy is something of a brat and a bully. He is a nuisance to his history teacher, Mr MacPherson, and leads a teenage gang called the Warriors. Unlike his brother, Duddy is a lacklustre student who passes through high school at the bottom of his class. He does, however, show entrepreneurial ambition early on, with his first money-making schemes in selling stamps and circulating Tijuana bibles. Duddy comes to have many loyal allies, but his own loyalties never extend beyond his own immediate family, including his grandfather, all of whom come to question his ambitions and means of making them happen.
Cuckoo Kaplan - A comedian at Rubin’s Hotel. During Duddy's summer at the hotel, Cuckoo Kaplan is Duddy's only trusted acquaintance. The friendship between Duddy and Cuckoo ends when Duddy tells Cuckoo that he lacks talent.
Yvette Durelle - An honest, hardworking young woman from Ste. Agathe whom Duddy meets while working at the hotel. Yvette takes Duddy on a walk deep into the mountains, where they stop at Lac St. Pierre. Duddy, excited about finding his dream land, entrusts Yvette with the deeds and secretarial work for his land acquisition and companies. Their relationship is strained by Duddy's constant swindling and tireless ambition. He is non-committal to his relationship with Yvette despite her genuine love for him and his being highly dependent on her.
Virgil Roseboro - An American with epilepsy whom Duddy meets on a trip to New York. Duddy sells Virgil’s smuggled pinball machines and then hires him to drive around and show films. Virgil is a loyal friend; despite Duddy's constant abuse Virgil remains in his service. He is highly literate, composing poetry in his spare time and eventually creating an Epileptic Awareness publication, intent on giving epileptics the same network of support as other minorities. Duddy eventually cheats Virgil out of money after the latter is severely injured in an accident.
Jacob Hersh - One of Duddy’s classmates, Hersh is a young communist and desires peace and order. He won a scholarship to McGill University but dropped out to become a writer.
Mr. John Alexander MacPherson A teacher at Fletcher Fields High School, which Duddy attends. He, unlike the other teachers, refuses to use corporal punishment on the students. MacPherson's wife is sickly and bedridden. One night while MacPherson is out, a prank phone call by Duddy to MacPherson's house pulls his wife out of bed, resulting in her death. When MacPherson returns to school, he uses corporal punishment on the boys and in his spare time begins drinking heavily.
Irwin Shubert - A 19-year-old boy whom Duddy first encounters while working in Ste. Agathe. Irwin is antagonistic to Duddy's ambition and cheats him out of his summer earnings through a night of rigged roulette. He is later one of the boys comprising Lennie's group of McGill friends.
Jerry Dingleman - Crippled from polio and walking with crutches, he is known as the Boy Wonder. Ten years ago he was a very poor, typical Jew living in Montreal. As the legend goes, he collected street car transfers off the street and sold them. (“He’s up a quarter in 2 hours. Selling at 3 cents a piece.") Rather than donating the money to poor Jews, he bet on horses and won. Over a period of time, he became rich through many business ventures, including overseeing a drug-smuggling enterprise.
Peter John Friar - A filmmaker blacklisted from Hollywood during the McCarthy raids. Duddy befriends him through a cinema club and together they start Duddy's company producing ludicrous avant-gardebar mitzvah films.
Sandra Calder - One of the girls from Lennie's university friends group. After she gets pregnant by her boyfriend, Lennie is pressured into performing an abortion on her, which could get him kicked out of medical school.
Hugh Thomas Calder - Sandra's father. Although he attempts to create a friendship with Duddy, he is turned away due to Duddy's unwillingness to set aside business. He is a millionaire who inherited, rather than earned, his money. Time Magazine called him “Bland, Brilliant Hugh Thomas Calder.”
Mr. Samuel Cohen - Owns a scrap yard in Montreal. He befriends Duddy and gives him some fatherly advice about the need to use immoral means to get ahead in business. He is the first person to agree to buy a bar mitzvah film from Duddy. The description of the overblown, arty film is one of the comic highlights of the novel.
Mr. Rubin - He is the owner of “Hotel Lac Des Sables” in Ste. Agathe where Duddy has his waiter job.
Linda Rubin - The spoiled daughter of Mr. Rubin. She somewhat unknowingly helps Irwin trick Duddy out of his summer earnings. Later she is seen as an escort for Dingleman.
Jane Cox - A middle aged women who has inappropriate interests in young school boys, Married to their favorite teacher Mr. Cox.
Olive Brucker - Used to be a "perfect" couple with Jerry Dingleman, but left him when he got polio. Later she is hinted to be a drug addict.