Mitochondria are increasingly recognized as central arbiters of cellular fate, placing them at the nexus of pulmonary health and disease. Beyond their canonical role in adenosine triphosphate (ATP) synthesis, these organelles are critical hubs for redox signaling, metabolic homeostasis, and programmed cell death. Mitochondrial dysfunction—a multifaceted condition characterized by impaired bioenergetics, excessive reactive oxygen species (ROS) production, aberrant dynamics, and defective quality control via mitophagy—is a unifying pathogenic feature in chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and pulmonary arterial hypertension (PAH). This dysfunction is also a critical determinant of severity in acute conditions like acute lung injury (ALI) and COVID-19 and is a key mechanistic driver of Long COVID. This review synthesizes the core mechanisms of mitochondrial impairment, delineates their specific contributions to this spectrum of pulmonary pathologies, and discusses the burgeoning field of mitochondria-targeted therapeutics. Strategies ranging from targeted antioxidants and metabolic modulators to novel regenerative approaches like mitochondrial transplantation are highlighted, with an expanded discussion on their limitations, challenges, and clinical implications. By framing mitochondrial integrity as a critical determinant of pulmonary disease, we underscore a pivotal axis for future diagnostic and therapeutic innovation.