On 20 June 1996, the flag of the United Nations was raised for the first time at "Haus Carstanjen" in Bonn-Plittersdorf in the presence of the then UN Secretary-General Boutros Boutros-Ghali. This was the birth of the UN City of Bonn. Initially, only the United Nations Volunteers Programme (UNV) resided there, but the Climate Change Secretariat (UNFCCC) followed soon after. In the meantime, the UN organizations have moved into the "new" high-rise building of the German Bundestag, affectionately known as "Langer Eugen" as well as into the adjacent "old" House of Representatives and the new "Climate Tower", which was inaugurated in 2020. These buildings form the core of the UN Campus in Bonn.

Today, the Campus comprises 26 United Nations organizations. The largest UN institutions in Bonn include the Climate Secretariat (UNFCCC), the Secretariat to Combat Desertification (UNCCD) and the Volunteers Programme. The newest institution to date was added at the end of March 2023, the United Nations Geodetic Centre of Excellence (UNGGCE). The main task of the centre is to coordinate the development of a globally coordinated geodetic infrastructure. This infrastructure includes, for example, observation stations and data and analysis centres worldwide. This is not only of central importance for earth observation and navigation applications, but also for topics such as stable living conditions, climate change or land use.

Around 1,000 employees now belong to the ever-growing "UN family". The thematic focus of the individual organizations ranges from species conservation and water supply to disaster risk management. The motto "Shaping a sustainable future" unites them all under a common thematic umbrella. They see themselves as responsible for contributing to the implementation of the United Nations Sustainable Development Goals (SDGs) with their specific work by supporting governments and people in finding answers and pathways for a sustainable future. The City of Bonn does not only see itself as a host to these UN organizations, but actively supports and ensures visibility for the work of the United Nations in Bonn. In addition, the city administration holds public events, such as a civic festival for United Nations Day in front of Bonn’s Old Town Hall, and participates in international UN programs, for example in the areas of water management and disaster prevention.

Today, Bonn is both an internationally renowned location of the United Nations and a globally recognized center for sustainable development. In addition to the UN organizations, the city is home to around 150 non-governmental organizations (NGOs), particularly from the development and humanitarian aid sectors. These include both German and many international organizations, such as the Forest Stewardship Council (FSC), the Right Livelihood College (RLC) or the International Paralympic Committee (IPC). Federal President Frank-Walter Steinmeier even called Bonn the "global capital of sustainability" in 2016. This organizational diversity makes for an ideal international working climate with positive synergy effects. The direct proximity to the World Conference Center Bonn (WCCB) and many important points of contact is a particular advantage for cooperation, facilitating close cooperation and contacts through short distances. A large number of scientific institutions, think tanks, federal institutions and other organizations from politics, business and science also contribute to the sustainability cluster.

The European Centre for Medium-Range Weather Forecasts (ECMWF) is one of the most important new establishments in recent years. It has been located in Bonn since 2021 and will employ up to 150 people in the near future. ECMWF is a world leader in global numerical weather prediction, climatology and a central component of the European infrastructure for weather forecasting and climate research.

Together, the various organizations, with their individual content, expertise and commitment, have shaped Bonn as an international location, making it an international center of excellence, a true Sustainability Hub, helping shape a sustainable future for all.

Another contribution to the international working environment in the City of Bonn is made by Deutsche Welle (DW), which was founded in 1953 and is located in the immediate vicinity of the UN Campus. Deutsche Welle is the foreign broadcaster of the Federal Republic of Germany, active online, via radio and TV. DW, which celebrates its 70th broadcasting anniversary in 2023, not only paints a comprehensive, multi-layered picture of Germany in an independent journalistic manner, but also presents global events and developments from different perspectives. In this way, it promotes understanding between cultures and peoples. In its 30-language programs, it places a special focus on sustainability issues and thus reaches many millions of people all over the world. On the occasion of its anniversary, Federal Chancellor Olaf Scholz thanked Deutsche Welle for its achievements: "When we celebrate 70 years of Deutsche Welle today, we are also celebrating 70 years in which a great service has been rendered to democracy by your station," said the Chancellor in his greeting. Since 2008, Deutsche Welle has hosted the annual DW Global Media Forum (GMF). More than 2,000 media professionals and decision-makers from politics, culture, business and science from over 120 countries come together for an interdisciplinary, intercultural exchange. The motto of the 2023 GMF is "Overcoming divisions".

The city of Bonn is recognized worldwide as the venue for many important conferences, in particular as the host city of the 23rd United Nations Climate Change Conference (COP 23) in 2017, for which more than 20,000 delegates and other participants travelled to the Rhine to take part in the climate negotiations. Bonn's reputation as a conference venue also includes the Afghanistan Talks at Petersberg near Bonn in 2001 and 2002, the Conference of the Parties on Biodiversity in 2008, and the United Nations Department for Public Information (DPI/NGO) Conference for Non-Governmental Organizations in 2011. UNESCO's World Heritage Committee met in Bonn in 2015. In 2022, Bonn hosted the G7 Foreign Ministers' Conference.

Every year in September, the Bonn SDG Days take place in Bonn, where the 17 Sustainable Development Goals of the United Nations are presented with the participation of many city departments as well as numerous local initiatives, NGOs, cultural institutions and the local business community.The „Bonn Climate Talks“, regularly held by the United Nations in the city, put Bonn at the center of the international climate process. In addition, there are other international conferences, such as the "Daring Cities", an important networking event for cities and regions in the climate crisis. The city on the Rhine facilitates constructive dialogue at national, international and supranational levels. In this way, impulses continue to radiate from Bonn around the world. Whether climate, desert, water, soil, gender justice, species protection or early warning systems – Bonn is an important center of competence for the environment and sustainable development.

With the World Conference Center Bonn (WCCB, situated) in the city’s Federal Quarter, Bonn has gained a large conference center, significantly adding to Bonn's attractiveness as a host for conferences. The former plenary hall of the Bundestag forms part of the conference center, giving it a unique flair

As the cradle of German democracy, Bonn is committed to the spirit of a united Europe. Accordingly, the City of Bonn is involved in numerous European city networks such as EUROCITIES and the Council of European Municipalities and Regions (CEMR), which give a common voice to the concerns and ideas of cities and municipalities for the future development of Europe.

Europe's presence has been felt in Bonn for decades. On 1 March 1954, for example, a press liaison office of the then "High Authority of the European Coal and Steel Community" began its work in Bonn – as the first ever branch office of the European institutions. Later, this became the Bonn Regional Representation of the European Commission. It serves as a link between the European Commission in Brussels and the public, politics and media on the Rhine, Main and Saar. The Bonn Regional Representation was expanded in 2016 to include a so-called Europe Point, an information office for citizens.