MillerCoors was formed in 2008 as a joint venture between SABMiller and Molson Coors to combine their brewing, marketing and sales operations in the United States.

[5][6] MillerCoors was announced as a joint venture between SABMiller and Molson Coors in October 2007 [7] and was approved by regulators on June 5, 2008.

[10] During the merger discussions between Molson Coors and SABMiller in 2015, the U.S. Department of Justice (DOJ) agreed to the proposed deal only on the basis that SABMiller "spins off all its MillerCoors holdings in the U.S.—which include both Miller- and Coors-held brands—along with its Miller brands outside the U.S." The entire ownership situation was complicated: "In the United States, Coors is majority owned [58%] by MillerCoors (a subsidiary of SABMiller) and minority owned by Molson Coors, though internationally it's entirely owned by Molson Coors, and Miller is owned by SABMiller.

"[11] SABMiller agreed to divest itself of the Miller brands by selling its stake in MillerCoors to Molson Coors.

This was part of a corporate restructuring that reorganized the company's four business units into Molson Coors North America and Molson Coors Europe and retired the MillerCoors corporate brand name.