Background: Glucagon-like peptide-1 (GLP-1)-based therapies offer significant cardiometabolic benefits. Obesity-related heart failure with preserved ejection fraction (HFpEF) arises from a complex interplay of increased lipids, chronic inflammation, and metabolic disturbances. These factors not only exacerbate the disease but also affect GLP-1 pathways, supporting the potential role of GLP-1-based therapies in targeting this condition. Objective: This review aimed to synthesize the current evidence on GLP-1-based therapy in HFpEF, focusing on mechanisms of action, clinical outcomes, and practical significance. Methodology: A narrative review using PubMed and Scopus was conducted, including studies published between January 2020 and March 2026. Evidence from randomized trials, pooled analyses, mechanistic studies, and observational data was incorporated. Results: GLP-1-based therapies, including semaglutide and tirzepatide, demonstrated significant improvements in symptoms, exercise capacity, and quality of life. These benefits are closely linked to weight loss, reduced inflammation, and improved congestion indices. Tirzepatide use has also been associated with a reduction in heart failure-related complications. The underlying mechanisms likely involve coordinated effects on metabolism, inflammation, hemodynamics, and cardiac remodeling. Current evidence suggests that its efficacy in improving morbidity rates is stronger than its efficacy in reducing mortality rates. Conclusions: GLP-1-based therapies offer a promising, phenotypically targeted approach to managing obesity-associated HFpEF. However, their long-term effects on mortality remain unclear, highlighting the need for further research. Further studies should refine patient selection and define optimal clinical integration.