惩罚一般是指因为某种不当的行为，所受的痛苦或损失。在刑法和行为主义的心理学中，有不同的定义。

有许多哲学家都提出了关于处罚的定义。常见的、被认为构成处罚的要件如下：

在斯金纳等行为主学的心理学中，惩罚是指对个体的行为，施予痛苦或剥夺利益，以使其不再从事该行为的方法。和一般意义不同的是，心理学中的惩罚并没有道德意hi涵。

惩罚有时又被称为所谓的「报复性侵略」或「道德性侵略」。它可见于多种社会性动物中，而这使得演化学者认为它是一种演化稳定策略，它会被选出是因为它有助于合作行为。

Punishment is the authoritative imposition of an undesirable or unpleasant outcome upon a group or individual, in response to a particular action or behaviour that is deemed unacceptable or threatening to some norm.

The unpleasant imposition may include a fine, penalty, or confinement, or be the removal or denial of something pleasant or desirable. The individual may be a person, or even an animal. The authority may be either a group or a single person, and punishment may be carried out formally under a system of law or informally in other kinds of social settings such as within a family. Negative consequences that are not authorized or that are administered without a breach of rules are not considered to be punishment as defined here. The study and practice of the punishment of crimes, particularly as it applies to imprisonment, is called penology, or, often in modern texts, corrections; in this context, the punishment process is euphemistically called "correctional process". Research into punishment often includes similar research into prevention.