The answer depends on what is meant by “most debt” – total amount in dollars or highest debt relative to the size of the economy (debt-to-GDP).

Who has the most debt?

  • By total national debt in dollars , the United States is the country with the largest government debt stock, running into tens of trillions of dollars and exceeding the debt of any other single nation.
  • By debt-to-GDP ratio among large, advanced economies, Japan has long been at or near the top, with government debt more than twice the size of its annual economic output.
  • Some smaller or crisis-hit economies (for example Sudan in some recent datasets) have even higher debt-to-GDP ratios, but on a much smaller economic base and with far lower total dollar debt than the US or Japan.

Two key ways to look at it

  • Total debt (in dollars)
    • Favors very large economies.
    • The US leads by a big margin simply because its economy and financial system are huge.
  • Debt-to-GDP ratio (percentage)
    • Measures how heavy the debt burden is relative to economic size.
    • Japan, and in some years countries like Sudan or Singapore, appear at the top of global rankings on this metric.

Why it’s a big discussion topic

  • High US debt attracts attention because it is tied to the world’s main reserve currency and largest government bond market, so shifts in US borrowing affect global interest rates, investment flows, and financial stability.
  • Very high debt-to-GDP ratios in countries like Japan or Sudan raise questions about long‑term sustainability, growth, and how these governments can service or roll over their obligations without triggering inflation, austerity, or default.

Simple takeaway

  • If you mean sheer size in dollars: the United States has the most debt.
  • If you mean the heaviest burden compared to the economy: recent rankings often put Japan or crisis‑affected countries like Sudan at or near the top for debt-to-GDP.

Information gathered from public forums or data available on the internet and portrayed here.