Background: Despite evidence from the broader caregiving literature about the interdependent nature of the caregiving dyad, few studies in heart failure (HF) have examined associations between caregiver and patient characteristics. Objective: The aim of this study is to quantitatively synthesize the relationships between caregiver well-being and patient outcomes. Methods: The MEDLINE, PsycINFO, and CINAHL databases were searched for studies of adult HF patients and informal caregivers that tested the relationship between caregiver well-being (perceived strain and psychological distress) and patient outcomes of interest. Summary effects across studies were estimated using random effects meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: A total of 15 articles meeting inclusion criteria were included in the meta-analysis. Taking into account differences across studies, higher caregiver strain was associated significantly with greater patient symptoms (Fisher z = 0.22, P < .001) and higher caregiver strain was associated significantly with lower patient quality of life (Fisher z = -0.36, P < .001). Relationships between caregiver psychological distress and both patient symptoms and quality of life were not significant. Although individual studies largely found significant relationships between worse caregiver well-being and higher patient clinical event-risk, these studies were not amenable to meta-analysis because of substantial variation in event-risk measures. Conclusions: Clinical management and research approaches that acknowledge the interdependent nature of the caregiving dyad hold great potential to benefit both patients and caregivers.