Engagement in children’s mental health treatment is strikingly low. This might be due to differences in perspectives about what it means to be engaged in treatment as well as the strategies that are most effective at engaging families, as little is known about how well consumers’ perspectives map onto current models of engagement and the empirical literature. This qualitative study examined family perspectives of (1) aspirational and actual engagement in treatment, (2) barriers that impeded engagement, and (3) engagement strategies they recommended their providers and agencies use. Four focus groups were conducted with 20 caregivers (ages 24–75), and 11 youth and young adults (ages 15–23). All participants were currently or formerly enrolled in children’s mental health services. Data were analyzed through consensual qualitative research methods. Findings revealed that youth and caregivers’ definitions of engagement included both attitudinal and behavioral components. Numerous barriers impeded components of aspirational engagement, and agency- and provider-related barriers were most pervasive. Youth reported more attitudinal barriers, whereas caregivers reported more behavioral barriers. Participants described advocacy (e.g., taking direct action to influence treatment) as a key engagement component; however, such advocacy often involved treatment non-adherence that could be interpreted by providers as disengagement. Families recommended strategies to strengthen the therapeutic relationship and build trust that are empirically supported. However, families described many experiences in which providers did not use these empirically supported strategies. Families also described some theoretically supported engagement strategies as having a negative impact on engagement. In sum, the findings suggest that providers should take an empowering family-centered treatment approach where they seek to understand and build upon clients’ engagement perspectives.