A "military brat" (and various brat derivatives) is a term for a person whose parent or parents have served full-time in the armed forces during the person's childhood. In conventional usage, the word "brat" used alone may be pejorative; in modern, especially American, usage; however, "military brat" is often not considered to be a derogatory term (and may in fact be seen as a term of endearment). The term is used in several English-speaking countries, especially Canada, Australia, New Zealand, the United Kingdom; but it is in the United States in particular that this term is ascribed to a collectively identifiable demographic (with extensive psychological research done on the group by U.S. Defense Department). Accordingly, this group is shaped by frequent moves, absence of a parent, authoritarian family dynamics, strong patriarchal authority, threat of parental loss in war, and a militarized family unit. While non-military families share many of these same attributes, military culture is unique due to the tightly knit communities that perceive these traits as normal. Although the children did not choose to belong to it, military culture can have a long-term impact on the children.

As adults, military brats can share many of the same positive and negative traits developed from their mobile childhoods. Having had the opportunity to live around the world, military brats can have a breadth of experiences unmatched by most teenagers. Regardless of race, religion, nationality, or gender, brats might identify more with other highly mobile children than with non-mobile ones. Some can struggle to develop and maintain deep, lasting relationships, and can feel like outsiders to U.S. civilian culture. Their transitory lifestyle can hinder potential for constructing concrete relationships with people and developing emotional attachments to specific places, which may later develop into psychologically developmental disorders (Post Traumatic Stress Disorder, Avoidant Personality Disorder, Separation Anxiety Disorder, etc.). But most assimilate quickly and well as they have to do so with each move.