Indian Oil Corporation is India’s flagship national oil company and downstream petroleum major. It is India's largest commercial enterprise, with a sales turnover of Rs. 2, 85,337 crore – the highest-ever for an Indian company – and a net profit of Rs. 2, 950 crore for the year 2008-09. IndianOil is also the highest ranked Indian company in the prestigious Fortune 'Global 500' listing, having moved up 11 places to the 105th position in 2009. Incorporated as Indian Oil Company Ltd. on 30th June, 1959, it was renamed as Indian Oil Corporation Ltd. on 1st September, 1964 following the merger of Indian Refineries Ltd. (established 1958) with it. Indian Oil and its subsidiaries account for approximately 48% petroleum products market share, 34% national refining capacity and 71% downstream sector pipelines capacity in India.

As the flagship national oil company in the downstream sector, IndianOil reaches precious petroleum products to millions of people everyday through a countrywide network of about 35,000 sales points. They are backed for supplies by 167 bulk storage terminals and depots, 101 aviation fuel stations and 89 Indane (LPGas) bottling plants. About 7,335 bulk consumer pumps are also in operation for the convenience of large consumers, ensuring products and inventory at their doorstep. IndianOil operates the largest and the widest network of petrol & diesel stations in the country, numbering over 18,278. It reaches Indane cooking gas to the doorsteps of over 53 million households in nearly 2,700 markets through a network of about 5,000 Indane distributors. IndianOil's ISO-9002 certified Aviation Service commands over 63% market share in aviation fuel business, meeting the fuel needs of domestic and international flag carriers, private airlines and the Indian Defence Services. The Corporation also enjoys a dominant share of the bulk consumer business, including that of railways, state transport undertakings, and industrial, agricultural and marine sectors.

IndianOil's world-class R&D Centre is perhaps Asia's finest. Besides pioneering work in lubricants formulation, refinery processes, pipeline transportation and alternative fuels, the Centre is also the nodal agency of the Indian hydrocarbon sector for ushering in Hydrogen fuel economy in the country. It has set up a commercial Hydrogen-CNG station at an IndianOil retail outlet in New Delhi this year. The Centre holds 214 active patents, including 113 international patents. IndianOil has joined the league of global technology providers last year with the selection of its in-house developed INDMAX technology (for maximising LPGas yield) for the 4 MMTPA Fluidised Catalytic Cracking (FCC) unit at the Corporation's upcoming 15 MMTPA grass roots refinery at Paradip in Orissa, as well as for the FCC unit coming up at BRPL. A wholly-owned subsidiary, IndianOil Technologies Ltd., is engaged in commercialising the innovations and technologies developed by IndianOil's R&D Centre.

Indian Oil Corporation Ltd. (IndianOil) is celebrating its Golden Jubilee in 2009. During its Golden Jubilee year Indian Oil Corporation has decided to establish a 'Chair Professor of Petroleum Technology' at IIT Kanpur for a faculty member working in environment friendly technologies in hydrocarbon sector.