Heart failure (HF) is a leading cause of morbidity and mortality worldwide, characterized by a complex pathophysiology and heterogeneous clinical trajectories. Circulating biomarkers have progressively moved from ancillary diagnostic tools to indispensable instruments that inform diagnosis, prognostication, and therapeutic guidance. B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) remain the cornerstones of biomarker-guided management, yet their interpretation is influenced by age, renal function, obesity, and atrial fibrillation. Cardiac troponins, originally validated for myocardial infarction, provide robust prognostic information in both acute and chronic HF by reflecting ongoing myocardial injury, while high-sensitivity C-reactive protein (hsCRP) captures systemic inflammation and its impact on outcomes. The scope of biomarker research has rapidly expanded to novel pathways. Galectin-3 (Gal-3) and soluble suppression of tumorigenicity-2 (sST2) are established mediators of fibrosis and remodeling, offering incremental prognostic value beyond natriuretic peptides. Growth differentiation factor-15 (GDF-15), myeloperoxidase (MPO), and mid-regional pro-adrenomedullin (MR-proADM) integrate systemic stress, congestion, and oxidative injury into risk assessment. More recently, non-coding RNAs-including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs)-have emerged as minimally invasive, pathophysiologically grounded biomarkers with diagnostic, prognostic, and even therapeutic implications. Looking ahead, multimarker strategies that combine complementary pathways provide a multidimensional perspective on HF progression and therapeutic response. Advances in high-throughput omics platforms and artificial intelligence (AI) promise to refine biomarker integration into precision medicine, enabling individualized risk stratification and therapy optimization. Altogether, biomarkers now represent essential pillars of modern HF care and hold the potential to transform management from population-based to personalized strategies.