A list of Indianan companies. Many well known Indiana companies have been included. While this list isn't definitive, these are most of the top businesses in the state of Indiana. As a country, the United States has encouraged entrepreneurship throughout much of its history. The state of Indiana is no exception to this rule, and new businesses are started in Indiana 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 Indiana.What are companies headquartered in Indiana? Take a look at this list and you'll find some great names you've heard of.