Felix Holt, the Radical is an 1866 social novel and political novel by the English author George Eliot. The novel deals with political conflicts in a small English town at the time of the 1832 Reform Act. The plot centres on an election in which Harold Transome, a local landowner, runs for the "radical cause" for tactical reasons, contrary to his family's conservative tradition. Transome's opportunism is contrasted by Felix Holt, a young working-class man who rebels against the corruption and injustice of his time. Another plotline concerns Esther Lyon, the stepdaughter of a nonconformist clergyman, who is the true heiress to the Transome estate without knowing it. She must ultimately choose between a future with Harold Transome or Felix Holt. Her choice symbolizes the novel's central conflict between different lifestyles and social ideas.

The story takes place in the fictional community of Treby in the English Midlands in 1832, at the time of the First Reform Act. Harold Transome, a local landowner, has returned home after a fifteen-year trading career in the Middle East and is now running for Parliament for the North Loamshire constituency. However, contrary to his family's conservative traditions, he intends to run as a Radical. This alienates him from his traditional allies and throws his mother, Mrs. Transome, into despair. Harold Transome gains the support of his conservative uncle, the rector of Little Treby, and hires his family lawyer, Matthew Jermyn, as his campaign agent.

Much of his campaign focuses on Treby Magna. In this village lives Felix Holt, who has recently returned to live with his mother after extensive travels in Glasgow. He meets Rev. Rufus Lyon, a nonconformist clergyman in Treby Magna, and his stepdaughter Esther. Felix and Mr. Lyon quickly become friends, but he seems to treat Esther with condescension. Both Felix and Rev. Lyon are inclined to the radical cause.

Harold Transome learns that Jermyn has mismanaged the Transome estate and embezzled money for himself. Transome remains silent during the election, but Jermyn tries to devise a plan to protect himself from future prosecution. Meanwhile, in the nearby mining town of Sproxton, Felix observes campaign activities for the radical cause. He is angered by the "treating" of workers with beer in exchange for their vocal support. Felix shares his concerns with Harold Transome, who reprimands John Johnson for his campaign methods. However, Jermyn convinces Transome not to intervene.

Rev. Lyon learns from Maurice Christian, the servant of the conservative candidate Philip Debarry, about the possible identity of Esther's biological father and decides to tell Esther the truth about her father. Esther's outlook on life changes when she learns that she is actually Rev. Lyon's stepdaughter. Her relationship with her stepfather deepens as she also strives to meet the high moral standards that Felix Holt has instilled in her. As Felix Holt sees the change in Esther's character, he begins to fall in love with her. However, both share the feeling that they are destined never to marry each other. Meanwhile, Rev. Lyon challenges Rev. Augustus Debarry to a theological debate. The debate is initially agreed upon but canceled at the last minute.

On election day, riots break out in Treby Magna. Drunken miners from Sproxton attack townspeople and wantonly destroy property. Felix Holt is caught up in the riots and tries to lead the miners away from the town. In the end, however, Felix Holt is charged with manslaughter of a policeman who was trying to quell the riots. Harold Transome loses the election to Debarry.

Harold Transome takes legal action against Jermyn for his mismanagement of the Transome estate. Jermyn counters by threatening to reveal the true owner of the Transome estate to the public. However, Maurice Christian informs the Transomes that the true owner of the estate is actually Esther Lyon. Harold Transome invites her to the Transome estate, hoping to persuade her to marry him. Harold and Esther develop a good relationship, and Esther also becomes more compassionate towards Mrs. Transome, whose despair has deepened. Esther feels torn between Harold Transome and Felix Holt. She compares a life of comfortable wealth with Harold Transome to a life of personal growth in poverty with Felix Holt. Meanwhile, at Felix Holt's trial, Rev. Lyon, Harold Transome, and Esther Lyon all vouch for his character, but he is still found guilty of manslaughter. Harold Transome and the Debarrys work to obtain a pardon for Felix Holt.

Harold Transome proposes marriage to Esther Lyon, with the eager support of Mrs. Transome. But despite Esther's feelings for Harold and Mrs. Transome, she rejects the proposal. In a confrontation between Jermyn and Harold Transome, it is revealed that Jermyn is Harold Transome's father. Harold no longer considers himself worthy of marriage to Esther. Esther also relinquishes her claim to the Transome estate. Felix Holt and Esther Lyon marry and move away from Treby with Rev. Lyon. Matthew Jermyn is eventually ruined and moves abroad. The Debarrys remain friends with the Transomes, and the past is never spoken of.