The G20 is made up of 19 countries and the European Union (EU). The 19 countries are Argentina, Australia, Brazil, Canada, China, Germany, France, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the United Kingdom and the United States.

Spain is a permanent invited guest to G20 meetings. Every year the country which holds the G20 presidency also invites countries to attend at its own discretion. This year Argentina has invited Chile and the Netherlands.

Countries which chair key regional groups – such as the African Union (AU), the Association for Southeast Asian Nations (ASEAN) and the New Partnership for Africa's Development (NEPAD) – are generally invited to the summit. This year these regional groups will be represented by Rwanda, Singapore and Senegal, respectively. The Caribbean Community (CARICOM) has also been invited by Argentina for this year's G20 and is represented by Jamaica.  SOURCE:https://www.g20.org