Like all of Jane Austen's novels, Emma is a novel of courtship and social manners. The majority of the book focuses on the question of marriage: who will marry whom and for what reasons will they marry: love, practicality, or necessity? At the center of the narration is the title character, Emma Woodhouse, a heiress who lives with her widowed father at their estate, Hartfield. Noted for her beauty and cleverness, Emma is somewhat wasted in the small village of Highbury but takes a great deal of pride in her matchmaking skills. Unique among other women her age, she has no particular need to marry: she is in the unique situation of not needing a husband to supply her fortune.
At the beginning of the novel, Emma's governess, Miss Taylor, has just married Mr. Weston, a wealthy ma who owns Randalls, a nearby estate. Without Miss Taylor as a companion, Emma feels suddenly lonely and decides to adopt the orphan Harriet Smith as a protègè. Harriet lives at a nearby boarding school and knows nothing of her parents. Emma concludes that Harriet's father must have been a gentleman and advises the innocent Harriet in virtually all things, including her choice of society. She suggests that Harriet does not spend any more time with the Martins, a local family of farmers whose son, Robert, has paid Harriet much attention. Instead, Emma plans to play matchmaker for Harriet and Mr. Elton, the vicar of the church in Highbury.
THe friendship between Emma and Harriet does little good for either of them, a fact which Mr. Knightley, a neighbor and old friend, immediately notices. Harriet indulges Emma's worst qualities, giving her opportunity to meddle and serving only to flatter her. Emma in turn fills Harriet Smith with grand pretensions that do not suit her low situation in society. When Robert Martin proposes to Harriet, she rejects him based on Emma's advice, thinking that he is too common. Mr. Knightley criticizes Emma's matchmaking because he views Robert Martin to be superior to Harriet; while he is respectable, she is from uncertain origins. Emma's sister, Isabella, and her husband, Mr. John Knightley, visit Highbury, and Emma uses their visit as an opportunity to reconcile with Mr. Knightley after their argument over Harriet. Yet, she still believes that Mr. Elton is a far more suitable prospect than Robert Martin.
At first Emma seems to have some success in her attempts to bring Harriet and Mr. Elton together. The three spend a good deal of leisure time together, and he seems receptive to all of Emma's suggestions. When Harriet is unable to attend the Westons' party on Christmas Eve, however, Mr. Elton focuses all of his attention solely on Emma. When they travel home by carriage from the party, Mr. Elton professes his adoration for Emma and dismisses the idea that he would ever marry Harriet Smith. Mr. Elton intends to move up in society and is interested in Emma primarily for her social status and wealth. Emma promptly rejects Mr. Elton, who is highly offended and promptly leaves Highbury for a stay in Bath.
Emma is shocked by her poor judgment of the situation and belief that Mr. Elton would be a good match for Harriet. She realizes that Mr. Knightley may have been correct in some of his advice to her, but she is still not convinced that Harriet should demean herself by associating with Robert Martin. After Mr. Elton's departure, Emma is forced to break the news to a broken-hearted Harriet.
The village of Highbury is impatiently anticipating the visit of Frank Churchill, Mr. Weston’s son from his first marriage. After the death of his wife, Mr. Weston sent the child to be raised by his wife’s family, acknowledging that he did not have enough wealth to provide for the boy. Frank is thought to be an ideal match for Emma and, without having met him, Emma agrees that his age and breeding make him a good suitor for her.
Another character who occupies Emma's thoughts is Jane Fairfax, the granddaughter of Mrs. Bates, the impoverished widow of the former vicar, and the niece of Miss Bates, a chattery spinster who lives with her mother. Jane is equal to Emma in every respect (beauty, education, talents) except for status and provokes some jealousy in Emma. Jane will soon visit Highbury because the wealthy family who raised her after her parents' death has gone on vacation.
In the meantime, Mr. Elton returns from Bath with news that he is engaged to a Miss Augusta Hawkins. This news, along with an awkward meeting with the Martins, greatly embarrasses poor Harriet.
Frank Churchill finally visits the Westons, and Emma is pleased to discover that he lives up to her expectations. Emma and Frank begin to spend time together, but she notices that he seems to be somewhat insubstantial and immature. He makes a day trip to London for the sole reason of getting his hair cut, an act that even Emma acknowledges is superficial. As Frank and Emma continue to spend more time in each other’s company, Mr. Knightley becomes somewhat jealous. He disapproves of Frank, convinced that his is not to be trusted, especially with Emma’s heart. Emma in turn becomes jealous as she suspects that Mr. Knightley might be in love with Jane Fairfax.
Emma’s friendship with Frank Churchill is bolstered by his seemingly shared disdain for Jane Fairfax. Frank confirms Emma’s suspicions that Jane might be involved with Mr. Dixon, a married man, even though this is only idle gossip. Soon afterward, Jane Fairfax receives a pianoforte from London, and Emma and Frank conclude that it was sent to her by Mr. Dixon.
Frank Churchill must abruptly leave Highbury when he learns that his aunt is unwell. She is an insufferable woman, proud and vain, and she exercises great authority over her nephew. Thinking that Frank is ready to process his love for her, Emma convinces herself that she is in love with him but is uncertain how to tell if her feelings are sincere. Finally, she realizes that she must not be in love with him because she is as happy with him absent as she was with him present.
Mr. Elton brings his new wife back to Highbury. She is a vapid name-dropper, who compares everything to the supposedly grand lifestyle of her relatives and addresses her new peers in Highbury with a startling lack of formality. Emma takes an instant dislike to her, and upon realizing this, Mrs. Elton takes a dislike to Emma.
When Frank Churchill returns, he and Emma sponsor a ball at the Crown Inn. It is generally assumed that Frank and Emma have formed an attachment, but Emma has already ceased to imagine Frank as her own suitor and perceived him as a potential lover for Harriet. During the ball, Mr. Elton takes the opportunity to humiliate Harriet, openly snubbing her in front of the other guests. Mr. Knightley undercuts this social slight by graciously dancing with Harriet in Mr. Elton’s stead.
The next day, while walking home, Harriet is attacked by a group of gypsy beggars, but Frank Churchill saves her. His gallant rescue becomes the talk of Highbury and leads Emma to confirm her belief that he would be a suitable match for Harriet. While discussing the event, Harriet admits that she has feelings for the man who saved her, though she does not explicitly name Frank Churchill. Thanks to this new infatuation, Harriet is finally past her heartbreak for Mr. Elton.
Mr. Knightley begins to suspect that Frank Churchill has a secret relationship with Jane Fairfax, but Emma laughs at him and continues to flirt with Frank Churchill. At an outing at Box Hill, Frank Churchill's bad influence over Emma comes to a head, and Emma insults Miss Bates to her face. Afterwards, Mr. Knightley severely scolds Emma for her behavior. When Emma visits Miss Bates to apologize, she discovers how much her insult has damaged her relationship with the family.
After the death of his aunt, Frank is suddenly free to reveal that he has been secretly engaged to Jane Fairfax. The engagement had to remain a secret because of his aunt’s disapproval and threat to disown him if he made a bad match. Frank Churchill’s flirtatious behavior toward Emma is revealed to be nothing more than a ruse meant to divert attention from his feelings for Jane. When Emma attempts to break the bad news of Frank Churchill’s engagement to Harriet, Emma learns that Harriet is actually in love with Mr. Knightley, who “rescued” her at the Crown Inn ball. With Harriet’s revelation, Emma realizes that she is in love with Mr. Knightley herself. Emma concludes that, not only has been put her friend in the position of yet another heartbreak, but she has done Harriet a great disservice by making her think that she could aspire to such heights of society.
Mr. Knightley soon professes his love for Emma, and they plan to marry. Yet there are two obstacles: first, if Emma were to marry, she would have to leave her father, who would not be able to bear the separation; second, she must break the news to Harriet. Mr. Knightley decides to move in to Hartfield after their marriage to allay Mr. Woodhouse's fears of being left alone. Harriet takes the news about Mr. Knightley well and soon after reunites with Robert Martin. The novel concludes with three marriages: Robert Martin and Harriet, Frank Churchill and Jane Fairfax, and finally, Mr. Knightley and Emma.