After serving in the Royal Air Force, James "Jim" Dixon decides to take a college teaching job rather than return to his hometown and a life of drudgery teaching high school. Still, he now hates everything about his life: his field of study, medieval history; his boss, Professor Welch; his students; his sometime girlfriend, Margaret Peel. He does, however, enjoy drinking and smoking and criticizing everything and everyone around him. When Dixon meets Christine Callaghan, his feelings for her inspire him to try to change his life. In the end sheer luck leads to a new job in London and a potentially bright future with Christine.
Christine Callaghan is young, attractive, and charming, and Dixon assumes she is altogether too good for him. On top of all her other charms, Christine lives in London—Dixon's dream destination. Christine acts as a foil to Margaret's awkwardness and desperation, and she offers Dixon the ideal escape from his unhappy relationship.
Professor Ned Welch is Amis's comic masterpiece. He plays the recorder, forgets what he's talking about, can barely drive his "wheezing" car, and delights in the accomplishments of his pretentious sons, Bertrand and Michel. He is also married to the terrifying Mrs. Welch. Professor Welch seems to take deep personal delight in testing Dixon's personal and emotional limits. Perhaps this action is purposeful, or perhaps he is truly clueless. In the end it doesn't matter. The professor stays at the college, singing madrigals and drinking tea into the foreseeable future.
Even more than his father, Professor Welch, Bertrand Welch is Dixon's nemesis. Loud, pretentious, and born with a silver spoon in his mouth, Bertrand seems to have everything Dixon covets: money, privilege, Christine, and a strong shot at a coveted job with Julius Gore-Urquhart. Dixon and Bertrand have a hilarious fistfight near the end of the novel; Dixon bests Welch but just barely.
Margaret Peel, Dixon's semigirlfriend, is a sad, lonely, and emotionally unstable female academic who contributes to Dixon's feelings of "stuckness." Dixon doesn't want to marry Margaret, but he feels sorry and responsible for her. However, she rebuffs his sexual overtures and gets wildly upset when she feels he isn't paying enough attention to her. When Margaret's ex-boyfriend, Catchpole, tells Dixon her suicide attempt was a sham, both men deem her malevolently neurotic. To a modern reader, Margaret may seem more sympathetic: she is an intelligent woman caught in an unliberated time.
Bill Atkinson is almost the only grownup in Lucky Jim. He works as an insurance salesman, and his humor and dissatisfaction with his life exemplify Dixon's fears for his own future. Atkinson often acts as Dixon's savior, pulling pratfalls and making phone calls to help his friend escape various obligations.
Julius Gore-Urquhart needs to hire a secretary, and Bertrand Welch is desperate to land the job. However, Gore-Urquhart gives it to Dixon instead, in part because the two share contempt for the strictures of polite society. Gore-Urquhart turns out to be Dixon's "luck"; the job will give him a new life in London, financial security, and proximity to Christine Callaghan.