Oil & Gas (or the "Petroleum" industry) includes the global processes of exploration, extraction, refining, transporting (often by oil tankers and pipelines), and marketing petroleum products.

The largest volume products of the industry are fuel oil and gasoline (petrol). Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics.

The industry is usually divided into three major components: upstream, midstream and downstream.