A minority group, by its original definition, refers to a group of people whose practices, race, religion, ethnicity, or other characteristics are fewer in numbers than the main groups of those classifications. However, in present-day sociology, a minority group refers to a category of people who experience relative disadvantage as compared to members of a dominant social group. Minority group membership is typically based on differences in observable characteristics or practices, such as: ethnicity (ethnic minority), race (racial minority), religion (religious minority), sexual orientation (sexual minority), or disability. Utilizing the framework of intersectionality, it is important to recognize that an individual may simultaneously hold membership in multiple minority groups (e.g. both a racial and religious minority). Likewise, individuals may also be part of a minority group in regard to some characteristics, but part of a dominant group in regard to others.

The term "minority group" often occurs within the discourse of civil rights and collective rights, as members of minority groups are prone to differential treatment in the countries and societies in which they live. Minority group members often face discrimination in multiple areas of social life, including housing, employment, healthcare, and education, among others. While discrimination may be committed by individuals, it may also occur through structural inequalities, in which rights and opportunities are not equally accessible to all. The language of minority rights is often used to discuss laws designed to protect minority groups from discrimination and afford them equal social status to the dominant group.