India is experiencing a steady demographic transition marked by a rising share of older persons, with significant implications for labour supply, social security systems, and productivity. As of 2025, about 11% of India’s population over 150 million people is aged 60 years and above, and this proportion is projected to exceed 20% by 2050, potentially reaching nearly 347 million older adults. While India still benefits from a large working-age population and a labour force participation rate (LFPR) around 60%, the growing old-age dependency ratio (about 10–11%) signals increasing economic pressure on workers and public finances. This study examines the economic impacts of population ageing on labour force dynamics, social security coverage, and productivity in India. Using a descriptive and analytical design based on secondary data from PLFS, government reports, and international databases, the paper analyses trends in ageing, labour participation, and pension coverage. The findings reveal a paradox: social protection coverage has expanded to over 64% of the population, yet only about 23–25% of workers are covered by formal pension systems due to the dominance of informal employment. Many older adults therefore continue working, often in low-productivity informal jobs. However, evidence suggests that healthy and skilled older workers can remain productive, and the emerging silver economy offers new growth opportunities. The study concludes that population ageing in India is a manageable but urgent policy challenge. Strengthening pension systems, promoting flexible retirement, increasing female labour participation, and investing in health and lifelong learning are essential to sustain productivity and fiscal balance. With timely reforms, ageing can be transformed from a fiscal burden into an opportunity for inclusive and sustainable economic development.