Raphaël Liégeois is a Belgian-Luxembourgish biomedical engineer and astronaut. Liégeois completed a doctorate at the University of Liège on the functioning of the human brain from 2011 to 2015, and then held post-doctoral appointments at the National University of Singapore and the École Polytechnique Fédérale de Lausanne. He has held a teaching and research position at the University of Geneva and the École Polytechnique Fédérale de Lausanne since 2021. He was selected as a member of the 2022 European Space Agency Astronaut Group.

The 2022 European Space Agency Astronaut Group is the latest class of the European Astronaut Corps. The selection recruited five "career" astronauts as well as 12 "reserve/project" astronauts. They are the fourth European Space Agency (ESA) astronaut class to be recruited.