The 54-year-old German will replace Jim O'Donnell, 61, who is retiring.
O'Donnell, a native of Scotland, has held the job since July 2008. Willisch will arrive in the United States on Sept. 1 and work alongside O'Donnell during a one-month transition.
Since May 2009, Willisch has been head of BMW Group's European sales outside of Germany. Before that he was president of BMW M GmbH, the brand's performance division in Munich.
He began his BMW career in 1996 as head of the sales office in Dusseldorf, Germany. He later ran the sales subsidiaries in Germany, Japan and Sweden.
O'Donnell, previously BMW's top executive in the United Kingdom, worked past the company's mandatory retirement age of 60. He leaves with BMW in good shape in the United States. Last month BMW outsold Mercedes-Benz to extend its lead as the top-selling luxury brand this year. And BMW is on track to outsell Lexus in the United States for the first time since 1997.