The United States has a wide array of companies and industries, making it difficult to select one as the most popular. Nevertheless, it is possible to narrow down the list and identify some of the biggest and most successful companies in the US, and their respective rankings. Apple Inc. is the most popular company in the nation, with a market capitalization of over $1.3 trillion. Amazon, Google, Microsoft, and Facebook are also among the most successful companies in the United States, with a combined market capitalization of over $6.6 trillion. These five companies are leaders in their respective industries and have established themselves as some of the most popular companies in the world.