Mansfield Park is a novel by Jane Austen, written at Chawton Cottage between February 1811 and 1813.

The main character, Fanny Price, is a young girl from a large and relatively poor family, who is taken from them at age 10 to be raised by her rich uncle and aunt, Sir Thomas, a baronet, and Lady Bertram, of Mansfield Park. She had previously lived with her own parents, Lieut. Price and his wife, Frances (Fanny), Lady Bertram's sister. She is the second child and eldest daughter, with seven siblings born after her. She has a firm attachment to her older brother, William, who at the age of 12 has followed his father into the navy. With so many mouths to feed on a limited income, Fanny's mother is grateful for the opportunity to send Fanny away to live with her fine relatives.

At Mansfield Park, Fanny grows up with her four older cousins, Tom Bertram, Edmund Bertram, Maria Bertram and Julia, but is always treated as something of a poor relation. Only Edmund, the second son, shows her real kindness. He is also the most good-natured of the siblings: Maria and Julia are vain and spoiled, while Tom is an irresponsible gambler. Over time, Fanny's gratitude for Edmund's thoughtfulness secretly grows into romantic love. Her other maternal aunt, Mrs. Norris, the local parson's wife, showers attention and affection on her Bertram nieces, particularly Maria, but is verbally abusive and mean-spirited toward Fanny. She tries to exclude Fanny from outings and other pleasures, even denying her a fire in her room.

A few years after Fanny arrives, Aunt Norris is widowed, moves into a cottage of her own, and becomes an ever-more constant presence at Mansfield Park. Sir Thomas offers the parsonage to a Dr. Grant, who moves in with his wife.

When Fanny is 16, the stern patriarch Sir Thomas leaves for a year to deal with problems on his plantation in Antigua. He takes Tom along in hopes that the experience will sober him up. Meanwhile Mrs. Norris has taken on the task of finding a husband for Maria Bertram and succeeds in introducing her favorite niece to Mr. Rushworth, a very rich and rather stupid man. Maria accepts his marriage proposal, subject to Sir Thomas's approval on his return.

About this time, the fashionable, wealthy, and worldly Henry Crawford and his sister, Mary Crawford, arrive at the parsonage to stay with Mrs. Grant, their half-sister. After a year in Antigua, Sir Thomas sends Tom home while he continues business alone. Although his wife is indolent almost to the point of disengagement, Sir Thomas feels confident about his family situation, relying on the officious Mrs. Norris and steady, responsible Edmund to keep life running smoothly.

The arrival of the lively, attractive Crawfords disrupts the staid world of Mansfield and sparks a series of romantic entanglements. Mary and Edmund begin to form an attachment, despite her original preference for Tom as the heir of Mansfield Park. Although Edmund worries that her often cynical conversation may mask a lack of firm principle, and Mary is unhappy that Edmund wants to become a clergyman, their mutual attraction grows.

Fanny fears that Mary has enchanted Edmund, and that love has blinded him to her flaws. (Also, of course, she is in love with him herself.) Meanwhile, during a visit to Mr. Rushworth's ancestral estate in Sotherton, Henry deliberately plays with the affections of both Maria and Julia, driving them apart. Maria believes that Henry is falling in love with her and treats Mr. Rushworth dismissively, provoking his jealousy. Although nobody is paying much attention to Fanny, she is highly observant and witnesses Maria and Henry in compromising situations.

Encouraged by Tom and his friend Mr. Yates, the young people decide to put on Elizabeth Inchbald's play Lovers' Vows; however, Edmund and Fanny both initially object, believing Sir Thomas would disapprove and feeling that the subject matter of the play, which includes adultery, is not appropriate. Eventually Edmund reluctantly agrees to take on the role of Anhalt, the lover of the character played by Mary Crawford. Besides giving Mary and Edmund plenty of scope for talking about love and marriage, the play provides a pretext for Henry and Maria to flirt in public.

When Sir Thomas unexpectedly arrives home in the middle of a rehearsal, the theatricals are abruptly terminated. Henry, whom Maria had expected to propose to her, leaves, and she feels crushed, realising that he does not love her. Although she neither likes nor respects Mr. Rushworth, she goes ahead and marries him to escape the oppressive atmosphere of Mansfield, and they leave for Brighton, taking Julia with them. Meanwhile, Fanny's improved appearance and gentle disposition endear her to Sir Thomas, who begins treating her a bit less distantly. With Maria and Julia gone, Fanny and Mary Crawford are naturally thrown into each other's company. Out of affection and because she knows it will please Edmund and his father, Mary goes out of her way to befriend Fanny.

Henry returns to Mansfield Park and decides to amuse himself by making Fanny fall in love with him. However, Fanny is steadfastly if secretly in love with Edmund, and the tables are turned when Henry actually falls in love with Fanny. To further his suit, he uses his family connections to raise Fanny's brother William to the rank of naval lieutenant, to Fanny's great joy. However, when he proposes marriage, Fanny rejects him out of hand, partially because she disapproves of his moral character, and also because she loves someone else. Sir Thomas is dismayed and startled by her refusal, since it is an extremely advantageous match for a poor girl like Fanny. He reproaches her for ingratitude, and believing it is all female timidity on Fanny's part, encourages Henry to persevere.

To bring Fanny to her senses, Sir Thomas sends her home for a visit to Portsmouth, hoping that the lack of creature comforts there will help her set a higher value on Henry's offer. She sets off with William, who is briefly on leave, and sees him off in his first command. At Portsmouth, she develops a firm bond with her younger sister Susan, but is taken aback by the contrast between her dissolute surroundings--noise, chaos, unpalatable food--and the environment at Mansfield. Henry visits her to try to convince her that he has changed and is worthy of her affection. Although Fanny still maintains that she cannot marry him, her attitude begins to soften, particularly as Edmund and Mary seem to be moving toward an engagement.

Henry leaves for London, and shortly afterward, Fanny learns that scandal has enveloped him and Maria. The two had met at a party and rekindled their flirtation, and Maria has left her husband for him. A national scandal sheet gets wind of the affair, Maria is exposed as an adulterous wife, Mr. Rushworth sues for divorce, and the proud Bertram family is devastated. To make matters worse, Tom has taken ill, and Julia, fearing that her father will essentially lock her up, has eloped with Tom's flighty friend Mr. Yates.

In the midst of this crisis, Fanny returns to Mansfield Park with her sister, Susan, now joyfully welcomed by all the family. A repentant Sir Thomas realizes that Fanny was right to reject Henry's proposal and now regards her as his daughter. During an emotional meeting with Mary Crawford, Edmund discovers that Mary does not condemn Henry and Maria's adultery, only that it was discovered. Her main concern is covering it up, and she implies that if Fanny had only accepted Henry, there would have been no affair. Edmund, who had idolized Mary, feels that her true nature has been revealed to him. He tells her so, returns to Mansfield, and goes ahead with plans to be ordained a minister.

While he is despairing of ever getting over Mary, Edmund comes to realize how important Fanny is to him. He declares his love for her, and they are married, and eventually they move to the Mansfield Park parsonage, where they live close to those they love best. Tom recovers from his illness, a steadier and better man for it, and Julia's husband, Mr. Yates, turns out to be not so empty-headed after all. Henry Crawford refuses to marry Maria, who is banished by her family to live "in another country," where she is joined by her aunt Mrs. Norris. Fanny becomes the effective moral center of Mansfield Park.