Oi or OI may refer to:
An oil tanker, also known as a petroleum tanker, is a merchant ship designed for the bulk transport of oil.
An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution.
An oil platform, offshore platform, or (colloquially) oil rig is a large structure with facilities to drill wells (optionally), to extract and process oil and natural gas, or to temporarily store product until it can be brought to shore for refining and marketing.
Oil sands, also known as tar sands, or more technically bituminous sands, are a type of unconventional petroleum deposit.
The Oil-for-Food Programme (OIP), established by the United Nations in 1995 (under UN Security Council Resolution 986) was established to allow Iraq to sell oil on the world market in exchange for food, medicine, and other humanitarian needs for ordinary Iraqi citizens without allowing Iraq to boost its military capabilities.
Oil reserves denote the amount of crude oil that can be technically recovered at a cost that is financially feasible at the present price of oil.
An oil refinery or petroleum refinery is an industrial process plant where crude oil is processed and refined into more useful products such as petroleum naphtha, gasoline, diesel fuel, asphalt base, heating oil, kerosene, and liquefied petroleum gas.
Oil and Natural Gas Corporation Limited (ONGC) is an Indian multinational oil and gas company headquartered in Dehradun, Uttarakhand, India.
An oil lamp is an object used to produce light continuously for a period of time using an oil-based fuel source.