This chapter examines Jevons’s political ideas in relation to utilitarianism and evolutionism. Jevons endorsed Bentham’s utilitarianism, according to which the ultimate goal of society was the greatest happiness. I argue that Jevons’s commitment to utilitarianism led him to set some boundaries to individual liberty for the sake of the greatest happiness. Consistent with his endorsement of utilitarianism, Jevons reconsidered his uncompromising support for free trade, which he held in his youth, and came to prioritise utilitarianism over liberalism. I will also show how he rejected the utilitarianism of Mill, who held that some pleasures were qualitatively superior to others, because for Jevons Mill’s version of utilitarianism made the greatest happiness unattainable. I will then argue that Jevons’s political thought was shaped by Spencer’s evolutionism. Like Spencer, Jevons believed that the human mind and character evolved over generations. Jevons also embraced Spencer’s view of evolution as a providential and necessary process. However, his conviction that the principle of utility had priority over individual liberty led Jevons to disagree with Spencer’s opposition to state intervention. In contrast to Spencer, Jevons held that social scientists should apply their knowledge, intervening to actively guide society towards happiness.