Harmful child detention and deportation policies, along with dehumanizing migrant narratives, are part of a global pattern of systemic oppression targeting people on the move. This paper reviews the psychological harms experienced by migrant children caused by detention, separation, and deportation, critiquing the limitations of trauma-focused, individual therapeutic approaches often adopted by service-oriented fields. Community psychology principles are presented as an alternative framework, emphasizing ecological and systemic approaches to design more just and humane immigration policies at societal, organizational, and community levels. The paper explores evidence of harm, the strengths and limitations of therapeutic approaches, and harmful policies such as Trump's zero-tolerance policy and emerging US deportation plans. It also highlights positive frameworks, including the UN Convention on the Rights of the Child, such as organizational policies and legal standards centered on the child's best interests. Using a social-ecological lens, the paper examines harmful policies that escalate risks, stressors, and barriers and highlights humane and protective factors. The authors examine how community psychology challenges oppressive systems, promotes community-based alternatives, and amplifies the voices of migrant children and families. These efforts underscore the transformative potential of community psychology in addressing immigration injustices through collective action and systemic change.