Within the heterogeneous group of diseases that constitute interstitial lung disease, biomarkers allowing for early disease identification could provide an opportunity for timely and tailored intervention to preserve lung function and quality of life. This review evaluates the current and emerging biomarkers that may enable personalized assessment in patients with interstitial lung disease to augment clinical decision-making. Interstitial lung diseases are often progressive and fatal, with no current therapies able to cure or reverse associated fibrotic processes. This is a narrative review synthesizing all relevant interstitial lung disease biomarker literature from 2003 onward, with a focus on existing and emerging biomarkers for refining approaches to clinically meaningful endpoints and management guidance. VALIDATED PHYSIOLOGIC BIOMARKERS IN INTERSTITIAL LUNG DISEASE Several physiologic biomarkers are well established for severity assessment and monitoring of ILD, although they have limited diagnostic utility.