Bilateral relations between Germany and the Kingdom of Tonga have traditionally been friendly. The German Empire signed a friendship treaty with Tonga on 1 November 1876. Diplomatic relations with the Federal Republic of Germany have been in place since 1976. The Treaty on Friendly Relations and Cooperation between the Federal Republic of Germany and the Kingdom of Tonga entered into force on 2 January 1978. Diplomatic contacts are maintained by the German Embassy in Wellington, New Zealand. In the country itself Germany is represented by an honorary consul in the capital Nuku’alofa. The Kingdom of Tonga’s mission in London is responsible for Germany.

Germany supports the development of the Pacific island nation through its contributions to the European Union’s Neighbourhood, Development and International Cooperation Instrument (NDICI) (until 2021 the European Development Fund (EDF)). The Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) and regional and local partners are implementing a regional programme focused on adapting to climate change, which is financed by German development cooperation funding, as well as other efforts including a regional project aimed at protecting marine and coastal biodiversity. There are also microprojects in the fields of infrastructure, education and vocational training, health, empowering women and combatting domestic violence. Following the volcanic eruption and tsunami in January 2022, Germany funded a local assistance project to provide clean drinking water and support community gardens.

Foreign Minister Wadephul visited Tonga in February 2026. He joined in celebrations to mark 150 years of the friendship treaty and 50 years of diplomatic relations between the Kingdom of Tonga and Germany.

Tonga is a member of the UN Group of Friends on Climate and Security, founded by Germany and Nauru.