The U.S. dollar (USD) is the currency most used in international transactions and is the world's foremost reserve currency, backed by its economy, its military, the petrodollar system and its linked eurodollar and large U.S. treasuries market.

• Currency code: USD
• Currency symbol: $, US$, U$
• Issuer: Federal Reserve
• Nicknames: greenback, buck, green, dough, smacker, bones, dead presidents, scrillas, paper