In the 2021-2022 fiscal year, the monthly average number of children and youth in care in Ontario was 8,700 (OACAS, 2022ₑ). Most of these young people have histories of developmental trauma and require safety, consistency, and predictability in order to heal. As such, placement stability is a key goal within child welfare. However, placement disruptions are common and often result in widespread negative outcomes for young people in care. Within the context of the many supports that must be offered to youths and resource parents, one area of intervention includes parenting support for resource parents. The overall objective of this two-study dissertation was to assess youth and caregiver associations with the number of youth placement changes and to address some of these factors by evaluating an in-service trauma-informed parenting program. For Study 1, hierarchical regression analyses examined youth and resource parent variables associated with the number of placement changes among 1,624 Ontario youths aged 10-17 years. Study 1 utilized data from 2017 previously collected as part of the Ontario Looking After Children project, which is an initiative designed to improve developmental outcomes for young people in care in Ontario. For demographic variables, parent-model placements (i.e., foster, adoptive, kinship homes) were associated with fewer changes than residential placements. Also, younger age when first placed in care, older current youth age, and a higher number of maltreatment types experienced by the youth were associated with a greater number of placement changes. For youth variables, greater conduct problems, peer problems, and prosocial behaviour, as well as fewer internal developmental assets, were associated with greater placement changes. For caregiver variables, lower placement satisfaction was associated with a greater number of placement changes. These findings highlight the importance of considering both youth and caregiver factors that are associated with placement changes and as such, provides insight into possible areas of intervention to increase placement stability for youths in out-of-home care. Building on these results, Study 2 involved conducting a preliminary evaluation of the Resource Parent Curriculum (RPC), which is an in-service, group-based parenting program developed by the National Child Traumatic Stress Network. This 8-module program was delivered virtually to resource parents in Ontario on six occasions during 2020-2021, with a total of 43 research participants. Youth and caregiver outcomes were examined by way of a quasi-experimental design that included 22 resource parents in the experimental group and 21 in the waitlist control and involved baseline, post-program, and 2-month follow-up assessments. In terms of resource parents' reactions, quantitative and qualitative results suggested that resource parents were highly satisfied with the program's content and delivery. For learning outcomes, RPC resulted in improvements in resource parents' knowledge and beliefs in trauma-informed parenting. While not statistically significant, post-hoc exploratory analyses revealed some potential small effects for improvements in resource parents' tolerance of challenging youth behaviours and in parenting self-efficacy. For behavioural outcomes among resource parents, several potential effects (not statistically significant) were noted with small to medium effect sizes regarding possible improvements in resource parents’ attachment relationship with their youth, increased social supports, improved family functioning, and reduced parenting distress. Study 2 was novel in being the first to evaluate RPC using a quasi-experimental design within a Canadian context and through virtual delivery. Findings highlighted both the benefits of the program as well as resource parents' ongoing training needs and required supports to improve youth well-being and placement stability.