Official development assistance (ODA) is a category used by the Development Assistance Committee (DAC) of the Organisation for Economic Co-operation and Development (OECD) to measure foreign aid. The DAC first adopted the concept in 1969. It is widely used as an indicator of international aid flow. It refers to material resources given by the governments of richer countries to promote the economic development of poorer countries and the welfare of their people. The donor government agency may disburse such resources to the government of the recipient country or through other organizations. Most ODA is in the form of grants, but some is measured as the concessional value in soft (low-interest) loans.

In 2019, the annual amount of state donor aid counted as ODA was US$ 168 billion, of which US$ 152 billion came from DAC donors.