Mr. Pickwick is the founder and Perpetual President of the Pickwick Club, a gentleman’s club, which he has named after himself. Pickwick petitions the club to allow him and his closest friends—Tracy Tupman, Augustus Snodgrass, and Nathaniel Winkle—to travel around and record their adventures and findings for the benefit of the other members of the club. The club agrees to the petition, and Mr. Pickwick and his friends begin a series of adventures together.
Early on, they meet Alfred Jingle, a charismatic conman who repeatedly makes the Pickwickians trust him, only to stab them in the back. Because of Jingle’s behavior, Winkle almost ends up in a duel. However, the Pickwickians also meet kind and generous people such as the Wardle family, who graciously welcome the Pickwickians, along with Jingle, into their home. Before long, Tupman finds himself falling in love with Rachael Wardle, the sister of the family patriarch, Mr. Wardle. When Jingle learns of this, he deliberately turns Rachael against Tupman and then runs away and marries her himself, all to get his hands on the Wardle family fortune. Ultimately, Pickwick and Mr. Wardle chase Jingle down and put an end to the marriage before it can truly begin. However, in order to do so, Mr. Wardle has to pay Jingle a fair bit of money. Jingle takes the money and then continues on his way, making Pickwick furious.
From this point forward, Pickwick makes it his mission to travel around and warn people of Jingle before he can cause more trouble. Around this time, he also hires a manservant, Sam Weller, who constantly stays by Pickwick’s side and works tirelessly to please him. While attending a party with the London elite, Pickwick learns that Jingle has been going around in a disguise, pretending to be someone named Charles Fitz-Marshall. When Jingle shows up at the party in disguise and sees Pickwick, he quickly runs away. Pickwick pursues Jingle to the town of Bury St. Edmunds, where Jingle fools Pickwick once again, this time with the help of his new manservant, Job Trotter. Because of Jingle and Trotter, the local law enforcement of Bury St. Edmunds think the Pickwickians are up to no good. However, after some confusion, Pickwick explains that Jingle is a fraud and exposes him to the townspeople. Although Pickwick is happy to vindicate himself, he is annoyed that, once again, Jingle simply just leaves the town to go terrorize another town.
In addition to his problems with Jingle, Pickwick also has a lawsuit brewing with Mrs. Bardell, his former landlady. Awhile back, Mrs. Bardell mistakenly got the idea that Pickwick intended to marry her. Now that she knows that is not the case, she is suing him for damages with backing from the dubious legal team Dodson and Fogg, who regularly use frivolous lawsuits to make money for themselves while exploiting the ignorant and less fortunate. While Pickwick is dealing with his legal troubles, Sam reconnects with his father, Mr. Weller, and his new stepmother, Mrs. Weller. Much to Mr. Weller’s disappointment, Mrs. Weller puts all of her time and energy into a Methodist group she has recently joined. One of the leaders of the group is named Stiggins, who regularly points fingers at others for their sinful nature, but never at himself. Sam and Mr. Weller hope to teach Stiggins a lesson when they get the chance.
Before Pickwick’s legal case officially gets underway, the Pickwickians return to Dingley Dell, the home of the Wardle family, to celebrate Christmas. There, they meet Bob Sawyer, Benjamin Allen, and Arabella Allen. Bob and Benjamin are medical students and best friends. Meanwhile, Arabella is Benjamin’s sister. Benjamin strongly hopes that Arabella and Bob will get married one day, claiming that no one else is good enough for her. This is a problem for Winkle, who almost immediately becomes romantically interested in Arabella.
After the Christmas celebration, the Pickwickians return to London for the Bardell v. Pickwick trial. During the trial, several of the Pickwickians take the stand, hoping to defend Pickwick, but they only make matters worse. The only person who helps at all is Sam, who manages to cast some doubt on the moral character of Dodson and Fogg. However, ultimately, the jury finds that Pickwick is liable to pay Mrs. Bardell. After the trial, Pickwick declares that he will not give Mrs. Bardell a penny—not because he cannot afford it, but because he refuses to do so on principal—he’d rather go to a debtor’s prison. The other Pickwickians attempt to get Pickwick to change his mind, but he refuses to see reason.
Wanting to distract himself, Pickwick suggests that the group travels to Bath together. The trip to Bath goes well for the most part, although some hijinks ensue. However, when the gang returns to London, Pickwick is arrested and taken to Fleet Prison for refusing to pay his debt to Mrs. Bardell. In prison, Pickwick sees how the other half lives. Many people are starving and barely clinging to life because the conditions in the prison are so poor. Meanwhile, Pickwick is able to secure a rather comfortable position in the prison for himself because he has the means to do so.
Because he refuses to leave Pickwick’s side, Sam purposely gets himself sent to prison as well, so he can continue to serve his master. Pickwick gets several other surprises while in prison. The first is that he finds Jingle and Trotter, who have fallen upon hard times. Although Jingle and Trotter have messed with Pickwick in the past, Pickwick takes sympathy on them and offers to help them out if he can. Then, shortly after Pickwick enters the prison, Mrs. Bardell goes to prison because she cannot afford to pay Dodson and Fogg for their work. Mrs. Bardell’s plight also moves Pickwick, despite the pain and embarrassment she has caused him. Ultimately, he decides to pay Mrs. Bardell’s debts as well as his own.
As Pickwick is getting out of prison, he learns about Winkle’s relationship with Arabella, which is still a secret to everyone else. Winkle is nervous about telling Benjamin and his father, Winkle Sr., both of whom will not approve of the marriage. Pickwick promises to help Winkle in this matter. First, Pickwick goes to see Benjamin to give him the news. Although Benjamin is irate at first, he quickly comes around. Then, Pickwick takes Benjamin and Bob with him to share the news with Winkle Sr. Unfortunately, Benjamin and Bob drink too much on the way and leave a horrible impression, making Winkle Sr. suspect that the marriage was a mistake. In addition, to helping Winkle during this time period, Pickwick also helps release Jingle and Trotter from jail. Both men thank him graciously and promise that they have changed their ways, though Pickwick has his doubts.
Meanwhile, Sam learns that his stepmother, Mrs. Weller, died suddenly. He goes to visit Mr. Weller to support him and help him sort everything out. Mr. Weller is sad about Mrs. Weller’s debt, though he takes some comfort in the fact that she left a reasonable amount of money behind—money he can use to help secure Sam a better future. While Sam is talking to his father, Stiggins shows up. Stiggins pretends to be sad about Mrs. Weller’s death, but it is clear that really, he is just hoping she left him some money. Irate, Mr. Weller forcibly dunks Stiggins head underwater and almost drowns him. Eventually, he lets Stiggins go, deciding that he has learned his lesson.
However, the issue of what to do with the money remains. Ultimately, Mr. Weller decides to give the money to Pickwick for safekeeping, deciding that Pickwick knows what to do with money and will use it responsibly. During his meeting with Pickwick, Mr. Weller and Pickwick also talk about the possibility of Sam marrying Mary, a housemaid Sam is fond of. Pickwick offers to arrange everything for Sam, wanting him to be happy. Although Mr. Weller thinks it is a good idea, Sam ultimately decides he is uninterested, instead preferring to stay by Pickwick’s side.
As Pickwick, Sam, and Mr. Weller are sorting out their business, Arabella gets a mysterious visitor, an old man who she does not recognize. While Arabella is talking to the old man, Winkle walks in the door and recognizes the man as his father. After talking to Arabella and Winkle for a short time, Winkle Sr. decides that he approves of the marriage after all, much to the delight of the couple. In a similar vein, Snodgrass has also found love; he has secretly been seeing Emily Wardle, Mr. Wardle’s daughter. Although Emily and Snodgrass try to find a good time to announce their relationship, Snodgrass gets caught in Emily’s room in a farcical scene before they get the chance, letting the secret out. Although Mr. Wardle is not pleased about how he discovered the relationship, he ultimately approves of it.
Because the Pickwickians all seem to be settling down, Pickwick decides that it is time to disband the Pickwick Club for good. After officially doing so, he buys a beautiful house in the countryside and offers to host Emily and Snodgrass’s wedding—an offer they happily accept. The novel comes to an end as everyone gets together to celebrate the marriage at Pickwick’s new home. It is one of the happiest days of Pickwick’s life.