NuStar Energy L.P. is a midstream energy company based in San Antonio, Texas, and a subsidiary of Sunoco LP. Founded in 2001, it is one of the largest independent liquids terminal and pipeline operators in the United States, with operations extending to Canada, Mexico, the Netherlands, the Caribbean, and the United Kingdom. The company manages an extensive network of approximately 8,700 miles of pipelines and 79 terminal and storage facilities, offering a combined storage capacity of about 93 million barrels.

NuStar's core services include the transportation of petroleum products and renewable fuels, as well as terminaling and storage for crude oil, refined products, specialty liquids, and renewable fuels like ethanol and biodiesel. The company markets these products to integrated oil companies, refining companies, and other customers, supporting their supply chain needs across North America and select international markets. NuStar is committed to safety, environmental stewardship, and sustainability in its operations, employing over 1,600 people globally.