Judicial activism is a judicial philosophy that refers to the practice of judges making rulings based on their policy views rather than their honest interpretation of the current law. It is sometimes used as an antonym of judicial restraint, which is characterized by a focus on stare decisis and a reluctance to reinterpret the law. The term "judicial activism" was coined by the American historian Arthur M. Schlesinger, Jr., in a 1947 article in Fortune.

Some scholars have posited dimensions along which judge courts may be perceived as activist, including majoritarianism, interpretive stability, interpretive fidelity, substance/democratic process, specificity of policy, and availability of an alternate policymaker. However, the term "judicial activism" is often maligned by judges and political pundits, and accusations of judicial activism are commonplace on both ends of the political spectrum.

Critics of judicial activism argue that it exceeds the proper exercise of judicial authority and risks upsetting the balance between the three branches of government. They also argue that judges are often ill-equipped to make sound public policy decisions and that judge-made policies are less likely to receive wide acceptance from the general public. However, proponents of judicial activism view it as a necessary check on legislative overreach and a way to enforce their own views of constitutional requirements rather than deferring to the views of other government officials or earlier courts.

Examples of judicial activism include Brown v. Board of Education, which ruled that racial segregation of children in public schools was unconstitutional. However, Dred Scott v. Sandford was also considered judicial activism, for the ruling that upheld slavery in the United States and denied the legality of Black identity as a human.

In summary, judicial activism is a judicial philosophy that refers to the practice of judges making rulings based on their policy views rather than their honest interpretation of the current law. It is often maligned by judges and political pundits, and accusations of judicial activism are commonplace on both ends of the political spectrum.