The COVID-19 pandemic had a significant impact on the mental health of young children, and schools are being tasked with providing greater support for their emotional well-being. While gratitude practices have proven beneficial for the mental health of adults, less is known about the efficacy of their use in promoting positive character development with children. The present study aimed to evaluate the impact of a three-fold gratitude intervention on a group of first grade students (N = 16). For 28 weeks, students used a gratitude journal, expressed gratitude to others through writing, and created a gratitude collage. Gratitude journal entries were coded for themes and pre-post intervention evaluations were administered. Results from a Wilcoxon Signed Rank test indicate the intervention had a significant impact on children's gratitude and well-being. This study is based on the Relational Developmental Systems (RDS) Theory which emphasizes that human development is plastic, and that programs that promote character development can result in positive personal change. It builds on research that has shown that gratitude can be fostered through regular practice and can have a positive impact on mental health. The study has implications for educators looking to support children's mental health and well-being in school by implementing a simple gratitude intervention.