Social engineering is a discipline in political science that refers to efforts to influence popular attitudes and social behaviors on a large scale, whether by governments or private groups. In the political arena, the counterpart of social engineering is political engineering.

For various reasons, the term has been imbued with negative connotations. However, virtually all law and governance has the effect of changing behavior and can be considered "social engineering" to some extent. Prohibitions on murder, rape, suicide and littering are all policies aimed at discouraging undesirable behaviors. In British and Canadian jurisprudence, changing public attitudes about a behaviour is accepted as one of the key functions of laws prohibiting it. Governments also influence behavior more subtly through incentives and disincentives built into economic policy and tax policy, for instance, and have done so for centuries.

In practice, whether any specific policy is labeled as "social engineering" is often a question of intent. The term is most often used by libertarians, free-market thinkers, and traditionalists as an accusation against anyone who proposes to use law, tax policy, or other kinds of state influence to change existing power relationships: for instance, between men and women, or between different ethnic groups. Political conservatives in the United States have accused their opponents of social engineering through the promotion of political correctness, insofar as it may change social attitudes by defining "acceptable" and "unacceptable" language or acts. The right (i.e. the social conservative movement) has itself been accused of social engineering due to its promotion of Abstinence-only sex education, the English-only movement, Sodomy laws and state sponsored school prayer.