Abstract Objective Grit—one’s “perseverance and passion for long-term goals” (Duckworth et al., 2007)—is distinct from resilience, one’s ability to bounce back after negative events. In healthy populations, both promote emotional well-being and quality-of-life (Datu et al., 2019; Sharkey et al., 2017). Limited research has investigated how grit and resilience affect emotional functioning after pediatric cancer. We hypothesized resilience would mediate grit’s effects on emotional functioning in pediatric cancer survivors. Methods Our clinically referred sample of 214 pediatric cancer survivors ages 4–25 years was predominantly lower- to upper-middle class (73%) and racially diverse (Caucasian = 53%, Hispanic = 25%, Black = 12%). We administered the parent-report Behavior Assessment System for Children, Third Edition (BASC-3; variables: Resiliency, Anxiety, Depression), parent-report Short Grit Scale, and self-report BASC-3 (variables: Sense of Inadequacy, Locus of Control). Multiple regression and simple mediation analyses were conducted. Results Overall, the sample demonstrated average grit and resilience. Leukemia and brain tumor survivors demonstrated greater grit and resilience than survivors of other cancers. Grit predicted Anxiety (p = 0.026), Depression (p = 0.001), and Sense of Inadequacy (p ≤ 0.001). Resiliency had a significant indirect effect on grit’s prediction of Anxiety (β = −0.107, 95% CI [−0.206, −0.011]) and Depression (β = −0.192, 95% CI [−0.271, −0.117]), but not Sense of Inadequacy (β = −0.055, 95% CI [−0.200, 0.102]). Conclusion Higher levels of grit predicted better emotional outcomes in pediatric cancer survivors. Grit affected anxiety and depression in this sample via resiliency. Exploratory analyses regarding cancer type and age at diagnosis will be described. Findings support the need for further research on “positive neuropsychology” factors affecting neuropsychological outcomes in pediatric cancer survivors.