Background: Chest expansion (CE) is a key clinical parameter used to evaluate thoracic mobility and respiratory performance. Age-related physiological changes in elderly individuals lead to reductions in chest wall compliance and respiratory muscle strength, contributing to compromised pulmonary function. However, normative reference values for CE in the geriatric population in Delhi NCR are insufficiently documented. Objective: This study aimed to establish normative CE values in older adults aged ≥60 years residing in Delhi NCR and to analyse the influence of age, gender, BMI, and comorbidities on CE. Methods: A cross-sectional study was conducted with 111 elderly participants (55 males, 56 females). CE was measured with a non-elastic tape at the fourth intercostal space, recording the difference between maximal inspiration and full expiration. Participants were categorised by age (60–69, 70–79, ≥80 years). Statistical analysis included Pearson’s correlation. Results: The mean CE was significantly greater in males (3.54 ± 0.62 cm) compared with females (2.98 ± 0.57 cm). CE showed a progressive decline with age, with the highest values in the 60–69 group (3.62 ± 0.58 cm) and the lowest in participants aged ≥80 years (2.76 ± 0.49 cm). Higher BMI and comorbidities such as hypertension and diabetes were associated with reduced CE. Conclusion: This study establishes normative CE values for older adults in Delhi and confirms that CE decreases significantly with advancing age, elevated BMI, and comorbidities, and is consistently higher in males. These findings provide clinically relevant benchmarks to support respiratory assessment and rehabilitation strategies in geriatric populations.