Here are the 20 biggest holders of U.S. government debt. . . 20. Republic of Ireland â $50 Billion As a country with just 4.2 million citizens, Ireland currently holds $50 billion in U.S. government debt. Between January 2008 and January 2009, Ireland increased its holding of American debt by 221%. 19. Germany â $56 Billion Germany is a member of the United Nations (UN), North Atlantic Treaty Organization (NATO), Group of Eight (G8), and Organization for Economic Co-operation and Development (OECD). It is a major economic power with the world's third largest economy by nominal GDP and the fifth largest in purchasing power parity. Germany is the world's largest exporter and second largest importer of goods. The central European country controls $56 billion in U.S. Treasuries. 18. Switzerland â $62 Billion The neutral, landlocked, alpine country, which hosts many international organizations including the Red Cross and World Trade Organization (WTO), owns just over $62 billion in U.S. debt. 17. Hong Kong â $72 Billion Renowned for its expansive skyline and natural setting, Hong Kong holds about $72 billion in U.S. government debt. Hong Kong is one of the world's leading financial capitals, a major business and cultural hub, and maintains a highly-developed capitalist economy. 16. Taiwan â $73 Billion As another advanced, high-income Southeast Asian economy, Taiwan owns about $73 billion in U.S. Treasuries. The country's technology industry plays a key role in the global economy, as Taiwanese companies manufacture a giant portion of the world's consumer electronics. 15. Luxembourg â $87 Billion With a population of less than 500,000, Luxembourg owns over $87 billion in American debt. The tiny country is a founding member of the European Union (EU), NATO, UN, Benelux, and the Western European Union, reflecting a political consensus in favor of economic, political, and military integration. 14. Depository Institutions â $107 Billion According to the Federal Reserve Board of Governors, depository institutions, such as commercial banks, savings banks, and credit unions, hold over $107 billion in government debt. 13. Russia â $120 Billion Russia is the largest country in the world, covering more than an eighth of the Earth's land area. With 142 million people, it is the ninth largest by population. The transcontinental country currently holds about $120 billion in U.S. debt. This figure increased 240% between January 2008 and January 2009. 12. United Kingdom â $124 Billion Britain was the world's first industrialized country and the world's foremost power during the 19th and early 20th centuries. Today, the United Kingdom currently holds $124 billion in U.S. debt securities and has the fifth largest economy in the world by nominal GDP. 11. Insurance Companies â $126 Billion The Federal Reserve Board of Governors lists insurance companies as holding $126 billion in Treasury securities. This group includes property-casualty and life insurance firms. 10. Brazil â $134 Billion Brazil is the fifth largest country in the world by geographical area, occupying nearly half of South America, and the fifth most populous country. The South American economic giant holds $134 billion in U.S. debt. 9. Caribbean Banking Centers â $177 Billion The U.S. Treasury identifies the Bahamas, Bermuda, the Cayman Islands, the Netherlands Antilles, Panama, and the British Virgin Islands as holding $177 billion in American debt. 8. Oil Exporters â $186 Billion Included in the group of oil exporters are Ecuador, Venezuela, Indonesia, Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, the United Arab Emirates, Algeria, Gabon, Libya, and Nigeria. The group combines for a total of approximately $187 billion held in U.S. government debt. 7. Other Investors â $413 Billion This diverse group includes individuals, government-sponsored enterprises, brokers and dealers, bank personal trusts, estates, and both corporate and non-corporate businesses for a total of $413 billion held in U.S. national debt. 6. Pension Funds â $456 Billion Pension funds control large amounts of cash, which is reserved for personal retirements, and are therefore obligated to make relatively safe investments, such as U.S. Treasury securities. This group includes both private and local government pension funds, totaling over $456 billion. 5. State and Local Governments â $523 Billion State and local governments hold over a half-trillion dollars in U.S. Treasuries. The level of investment has remained very stable over the past three years, moving within the range of $517 billion and $550 billion from 2006 to 2009. 4. Japan â $635 Billion As another major U.S. trade partner, the archipelago country of Japan holds a huge amount of America's debt with a stunning $635 billion. Japan has the world's second largest economy by nominal GDP and the third largest in purchasing power parity. 3. Mainland China â $740 Billion The economy of Mainland China is the second largest in the world after that of the United States with a GDP of almost $8 trillion by purchasing power parity. China has been the fastest-growing major nation for the past quarter of a century with an average annual GDP growth rate above 10%. As one of the world's continuous civilizations, consisting of states and cultures dating back more than six millennia, China now controls approximately $740 billion in U.S. debt. 2. Mutual Funds â $769 Billion Mutual funds hold the second largest amount of American debt compared to any other group. Including money market funds, mutual funds, and closed-end funds, this group of investments manages approximately $769 billion of U.S. Treasury securities. 1. The Federal Reserve and U.S. Intragovernmental Holdings â $4,806 Billion This probably comes to you as no surprise. The largest holder of U.S. government debt is the privately-owned Federal Reserve. The Federal Reserve system of banks and other U.S. intragovernmental holdings accounts for a stunning $4.8 trillion in U.S. Treasury debt. And with recent announcements from the Fed, another potential $1 trillion may be added to its balance sheet.