Charles University is a member of the European University Alliance (4EU+), a partnership of eight leading European universities: Heidelberg Universität, Paris-Panthéon-Assas University, Sorbonne Université, University of Copenhagen, Université de Genève, Università degli Studi di Milano, University of Warsaw and Charles University. This partnership allows students and staff to participate in a wide range of educational, scientific or leisure activities - courses or summer schools, both face-to-face and online.

The University also has agreements with many universities around the world. These allow students to participate in educational and research stays or internships, language courses, winter/summer schools, etc. The University has agreements with institutions in 28 countries around the world, including the United States, Japan and Israel.