Discrimination experiences are among the dominant conditions that define racial and ethnic populations in the United States. Although scholars in the social sciences have investigated the relationship between racial discrimination and various outcomes, less is known about how the sources of discrimination may vary within populations. Most studies and theories driving those studies assume that racial and ethnic minorities are being discriminated against by members of the dominant group. The authors test this assumption using the Latino National Survey, a nationally representative survey of 8,634 Latinos. Nearly 40 percent of Latinos in this rich sample report being discriminated against by other racial or ethnic minorities, many indicating that they were discriminated against by other Latinos. The authors then examine whether the race of the discrimination agent matters and find that the relationship between discrimination and group identity is dependent on the race of the discrimination agent. Although discrimination from out-groups (i.e., whites and blacks) motivates greater linked fate and perceptions of commonality among Latinos, internal discrimination negatively affects these two outcomes. Thus, contrary to discrimination from either whites or African Americans, internal discrimination actually suppresses a sense of group identity among Latinos. This work could similarly inform collective theories and measurement approaches in this area and should therefore be perceived as an important and timely modification to our research methodologies.