Pirfenidone is a groundbreaking antifibrotic agent that has become a cornerstone in managing fibrotic interstitial lung diseases (ILDs), particularly idiopathic pulmonary fibrosis (IPF). This review comprehensively analyzes pirfenidone's mechanisms of action, clinical efficacy, safety profile, and emerging applications beyond IPF. Pirfenidone exerts its therapeutic effects by inhibiting key pathways involved in fibrosis, including transforming growth factor-beta (TGF-β) and other pro-fibrotic cytokines. It also reduces oxidative stress and inflammation. Clinical trials have consistently demonstrated pirfenidone's ability to slow the decline in lung function, reduce disease progression, and improve survival rates in IPF patients. Furthermore, emerging evidence supports its potential use in other fibrotic ILDs and non-pulmonary fibrotic conditions, such as liver and kidney fibrosis. Despite its proven benefits, pirfenidone's safety and tolerability profiles require careful monitoring, with gastrointestinal and photosensitivity reactions being the most common adverse effects. Future research is poised to explore combination therapies, personalized treatment approaches, and novel applications of pirfenidone in a broader range of fibrotic disorders. As the field of antifibrotic therapy advances, pirfenidone remains a pivotal agent with the potential to significantly impact the management of fibrotic diseases across multiple organ systems. This review aims to provide clinicians and researchers with a detailed understanding of pirfenidone's current role and prospects in treating fibrosis.