Cardiovascular magnetic resonance (CMR) imaging has become a cornerstone in the diagnosis, risk stratification, and management of cardiovascular disease (CVD), particularly heart failure (HF) and cardiomyopathies. Renowned as the gold standard for non-invasive quantification of ventricular volumes and ejection fraction, CMR delivers superior spatial and temporal resolution with excellent tissue-blood contrast. Recent advancements, including T1, T2, and T2* mapping, extracellular volume quantification, and late gadolinium enhancement, enable precise tissue characterization, allowing early detection of myocardial changes such as fibrosis, edema, and infiltration. These features provide critical insights into the pathophysiological mechanisms underlying HF phenotypes and diverse cardiomyopathies, enhancing diagnostic accuracy and guiding therapeutic decisions. This review explores the expanding role of CMR in CV disease, highlighting its diagnostic value in HF and in several cardiomyopathies, as well as its contribution to improving patient outcomes through detailed tissue characterization and prognosis.