A list of Wisconsin companies. Many well known Wisconsin companies have been included. While this list isn't definitive, these are most of the top businesses in the state of Wisconsin. As a country, the United States has encouraged entrepreneurship throughout much of its history. The state of Wisconsin is no exception to this rule, and new businesses are started in Wisconsin daily, ranging from corporations to LLCs to partnerships to sole proprietorships. This list, however, is mostly focused on the largest corporations in the state of Wisconsin.What companies are headquartered in Wisconsin? This list will answer that question and you may be surprised to see what companies are based in the Badger State.