The university campuses of Oldenburg and Groningen share a longstanding, interdisciplinary collaboration, founded in 1980 through a cooperation agreement. The University of Groningen counts as one of the longest and most intensive university partnerships of the University of Oldenburg. Furthermore, the University of Groningen is a member of the Association of North German Universities, to which the University of Oldenburg also belongs.

In 2012, the European Medical School Oldenburg-Groningen launched a major project, establishing a joint study program in human medicine that remains unique throughout Europe.

As a result, in 2014, the University of Groningen was declared a strategic partner university within the internationalization process of the University of Oldenburg.

On October 29, 2020, the two universities renewed their 40-year cooperation. During a ceremonial event, the cooperation agreement, which for the first time explicitly mentions the areas of teacher education and knowledge and technology transfer, was extended for another ten years.

Shortly afterwards, the 'Roadmap for Cooperation 2020-2030' was developed as a plan to further expand and strategically deepen the cooperation between the two universities. The Roadmap was endorsed in spring 2021 by the presidencies of Carl von Ossietzky University Oldenburg and the University of Groningen.

On January 31, 2025, the universities of Bremen and Oldenburg established the Northwest Alliance. The goal of the Northwest Alliance is to create a joint research and transfer area to make the top-level research concentrated in the northwest more visible internationally. The privileged international partner of this alliance is the University of Groningen.