Special drawing rights (SDRs) are supplementary foreign exchange reserve assets defined and maintained by the International Monetary Fund (IMF). Not a currency, SDRs instead represent a claim to currency held by IMF member countries for which they may be exchanged. As they can only be exchanged for euros, Japanese yen, pounds sterling, or US dollars, SDRs may actually represent a potential claim on IMF member countries' nongold foreign exchange reserve assets, which are usually held in those currencies. While they may appear to have a far more important part to play, or, perhaps, an important future role, being the unit of account for the IMF has long been the main function of the SDR.

Created in 1969 to supplement a shortfall of preferred foreign exchange reserve assets, namely gold and the US dollar, the SDR's value is defined by a weighted currency basket of four major currencies: the Euro, the US dollar, the British pound, and the Japanese yen. SDRs are denoted with the ISO 4217 currency code XDR.