Psychological operations (PSYOP) are operations to convey selected information and indicators to audiences to influence their motives and objective reasoning, and ultimately the behavior of governments, organizations, groups, and large foreign powers.

The purpose of United States psychological operations is to induce or reinforce behavior perceived to be favorable to U.S. objectives. They are an important part of the range of diplomatic, informational, military and economic activities available to the U.S. They can be utilized during both peacetime and conflict. There are three main types: strategic, operational, and tactical. Strategic PSYOP includes informational activities conducted by the U.S. government agencies outside of the military arena, though many utilize Department of Defense (DOD) assets. Operational PSYOP are conducted across the range of military operations, including during peacetime, in a defined operational area to promote the effectiveness of the joint force commander's (JFC) campaigns and strategies. Tactical PSYOP are conducted in the area assigned to a tactical commander across the range of military operations to support the tactical mission against opposing forces.

PSYOP can encourage popular discontent with the opposition's leadership, and by combining persuasion with a credible threat, degrade an adversary's ability to conduct or sustain military operations. They can also disrupt, confuse, and protract the adversary's decision-making process, undermining command and control. When properly employed, PSYOP have the potential to save the lives of friendly or enemy forces by reducing the adversary's will to fight. By lowering the adversary's morale and then its efficiency, PSYOP can also discourage aggressive actions by creating indifference within their ranks, ultimately leading to surrender.

The integrated employment of the core capabilities of electronic warfare, computer network operations, psychological operations, military deception, and operations security, in concert with specified supporting and related capabilities, to influence, disrupt, corrupt or usurp adversarial human and automated decision making while protecting our own.

Between 2010 and 2014, PSYOP was renamed Military Information Support Operations (MISO), then briefly renamed PSYOP in August 2014, only to return to MISO shortly thereafter in 2015. The term was again renamed back to PSYOP in October 2017.

PSYOP involves the careful creation and dissemination of a product message. There are three types of products that are used to create these messages. They include White products which are used in overt operations and Gray or Black products which are used in covert PSYOP. White, Gray, and Black don't refer to the product's content but rather the methods used to carry out the operation.

In order for PSYOP to be successful they must be based in reality. All messages must be consistent and must not contradict each other. Any gap between the product and reality will be quickly noticed. A credible "truth" must be presented which is consistent to all audiences. Primarily it is a component of offensive counterinformation but can be used defensively as well.

PSYOP are used in support of special operations, unconventional warfare, and counterinsurgency (COIN) operations. PSYOP can include military operations other than warfare and also include joint operations. They include counterterrorism operations, peace operations, noncombatant evacuation, enforcement of sanctions and maritime interception operations, strikes and raids, etc.