The Mating Season is a novel by P. G. Wodehouse, first published in the United Kingdom on 9 September 1949 by Herbert Jenkins, London, and in the United States on November 29, 1949, by Didier & Co., New York.

Featuring the well-intentioned Bertie Wooster and his resourceful valet Jeeves, the novel takes place at Deverill Hall, where Esmond Haddock lives with his five overcritical aunts. The story concerns the relationships of several couples, most notably Gussie Fink-Nottle and Madeline Bassett, Esmond Haddock and Corky Potter-Pirbright, and Catsmeat Potter-Pirbright and Gertrude Winkworth.

On the cue "five aunts" I had given at the knees a trifle, for the thought of being confronted with such a solid gaggle of aunts, even if those of another, was an unnerving one. Reminding myself that in this life it is not aunts that matter but the courage which one brings to them, I pulled myself together.

Bertie's overbearing Aunt Agatha orders him to go to Deverill Hall, King's Deverill, Hants., to stay with some friends of hers and perform in the village concert. Jeeves, who knows about Deverill Hall because his uncle Charlie Silversmith is the butler there, says that Esmond Haddock, his aunt Dame Daphne Winkworth, four other aunts, and Dame Daphne's daughter Gertrude Winkworth live there. Bertie's friend Gussie Fink-Nottle will also go there. Gussie is upset because his fiancée Madeline Bassett was supposed to accompany him, but had to visit a friend, Hilda Gudgeon, instead.

Another friend of Bertie's, Catsmeat Potter-Pirbright, an actor, wants to marry Gertrude. However, the aunts disapprove of actors. Catsmeat thinks Esmond is wooing Gertrude and asks Bertie to keep them apart. In exchange, Catsmeat will keep Gussie from brooding about Madeline; Bertie does not want Gussie and Madeline to split up because Madeline is resolved to marry Bertie if she does not marry Gussie. Bertie is also visited by Catsmeat's sister, Corky, who is arranging the village concert and wants Bertie to play Pat in a comedic Pat-and-Mike crosstalk act. Corky loves Esmond but won't marry him until he stands up to his domineering aunts, who disapprove of Corky because she is an actress. She believes Esmond has moved on to Gertrude. While drunk, Catsmeat makes Gussie wade through the Trafalgar Square fountain, and Gussie is sentenced to fourteen days in jail. To keep Madeline from learning about this, Jeeves suggests Bertie stay at Deverill Hall pretending to be Gussie. Bertie does so, taking Corky's dog Sam Goldwyn (a reference to film producer Samuel Goldwyn) with him at Corky's request.

At Deverill Hall, Bertie ("Gussie") learns that Esmond is in love with Corky and not Gertrude. Esmond hopes to win applause at the concert by singing a hunting song to impress Corky. Catsmeat, wanting to be near Gertrude, comes to the Hall pretending to be Bertie's valet Meadowes. The next day, Gussie, who was let off with a fine, arrives, pretending to be Bertie, along with Jeeves, who acts as "Bertie's" valet. Jeeves, believing that applause at the concert would give Esmond the courage to defy his aunts and marry Corky, starts assembling a claque. Gussie will take Bertie's place in the crosstalk act, with Catsmeat as his partner. Bertie will take Gussie's place by reciting Christopher Robin poems.

Catsmeat tells Bertie that Bertie's Aunt Agatha is coming to the house. Following a plan from Jeeves, Catsmeat asks Corky to invite Aunt Agatha's young son Thomas to visit her; Thomas, a fan of Corky's, runs away from school to see her, and Aunt Agatha cancels her trip when she learns her son has disappeared. Catsmeat tries to cheer up Queenie, the Hall's parlourmaid, who is distraught after ending her engagement to the local policeman Constable Dobbs, because he is an atheist.

Gussie, who has fallen for Corky, writes to Madeline ending their engagement. Bertie intercepts the letter, despite briefly running into Madeline and Hilda, and returns to King's Deverill. Thomas has arrived. He has a rubber cosh and hopes to hit Constable Dobbs, since Dobbs arrested Corky's dog Sam after Sam bit him. Silversmith announces that Queenie, his daughter, is engaged to Catsmeat ("Meadowes"); Queenie had to tell her father they were engaged after he saw Catsmeat trying to comfort her with a kiss.