South-South Cooperation is a framework for collaboration among countries of the South. These countries are often referred to as developing countries, the Third World, or the Global South. South-South collaboration involves two developing countries, but can also take the form of regional cooperation or global cooperation.

Other organizations have their own definitions of South-South cooperation. The United Nations Development Program (UNDP) has a Special Unit for South-South Cooperation. It defines the term as "a means of promoting effective development by learning and sharing best practices and technology among developing countries." UNDP’s official day for South-South Cooperation is 19 December.

Japan International Cooperation Agency (JICA) defines South-South cooperation as,  "Mutual cooperation aimed at fostering self-sustaining development, involving deepening relations among developing countries while conducting technical and economic cooperation."

See UN's terminology database for translations: http://unterm.un.org/