Big Brothers Big Sisters (BBBS) is a national non-profit organization that facilitates one-on-one mentoring between at-risk youth and adults in order to build developmental assets and promote the well-being of youth. The organization utilizes mentoring to facilitate strong, caring relationships that help marginalized youth realize their potential. The Great Lakes Bay Chapter of BBBS (Midland, Michigan) seeks to expand positive psychology resources and curriculum to: (a) bring together staff, mentors, mentees, and parents with a common language; (b) build and support strong relationships; and (c) enhance well-being in youth. This project provides a character strengths curriculum to support these goals. The project includes a train-the-trainer model and implementation recommendations to pilot the curriculum at the Great Lakes Bay chapter. If impactful, BBBS can adapt and scale the curriculum for other programs. To meet the diverse needs of the mentees, a research-informed Positive Psychology Playbook is included. The playbook is an expertise kit covering eight topics relevant to the development of at-risk youth. These topics, which include gratitude, grit, growth mindset, optimism, resilience, self- efficacy, character strengths and positive relationships, further equip the Great Lakes Bay Chapter with positive psychology knowledge, tips, and activities to support the development and well-being of marginalized youth.