The United States Agency for International Development (USAID) is an independent agency of the United States government that is primarily responsible for administering civilian foreign aid and development assistance. With a budget of over $50 billion, USAID is one of the largest official aid agencies in the world and accounts for more than half of all U.S. foreign assistance—the highest in the world in absolute dollar terms.

In the United States government, independent agencies are agencies that exist outside the federal executive departments and the Executive Office of the President. In a narrower sense, the term refers only to those independent agencies that, while considered part of the executive branch, have regulatory or rulemaking authority and are insulated from presidential control, usually because the president's power to dismiss the agency head or a member is limited.