Nauru was granted full membership of the Commonwealth in May 1999 and was admitted as the 187th member of the United Nations on 14 September 1999. It is also a member of several regional bodies including the Pacific Island Forum, Pacific Community (SPC), the Asian Development Bank, ESCAP and other specialised agencies. Nauru has a particular interest in international environmental issues, including global warming.

In Australia, Nauru is represented by a Consul-General in Melbourne. Elsewhere, Nauru is represented by a Permanent Representative to the United Nations in New York, a High Commissioner in Suva and Honorary Consuls in New Delhi and London. 

In Nauru, Australia is represented by a Consul-General.  The Peoples Republic of China has the only other diplomatic mission in Nauru. The Australian High Commissioner in Suva, Fiji, is accredited as Australia's non-resident High Commissioner for Nauru.

The United States does not have an embassy in Nauru; the US Ambassador to Fiji is accredited to Nauru.