ONGC’s landmark achievement came in 1974 with the discovery of the Mumbai High oilfield, a find that made India largely self-sufficient in oil through the 1980s. This success catalysed the growth of refineries, petrochemical plants, and fertiliser units, laying the foundation of India’s modern energy infrastructure. By the 1990s, as domestic production began to plateau and demand surged, ONGC evolved into a corporate entity under the 1994 Act, emerging as the nation’s most profitable public enterprise. Today, even as India imports over 85% of its crude oil, ONGC continues to anchor the nation’s energy security. It has diversified into refining through its acquisition of Hindustan Petroleum and expanded abroad via ONGC Videsh, with projects spanning 15 countries. Yet, the company faces fresh challenges from bureaucratic inertia to the global energy transition. As it invests in enhanced recovery and explores greener technologies, ONGC remains not just a legacy of India’s industrial rise, but a vital force shaping its energy future.