Stefan Ritt is a German physicist and head of the muon physics group[1] at the Paul Scherrer Institute, Aargau, Switzerland.

He is member of the MEG experiment and co-spokesperson of the Mu3e experiment.

He is best known for the development of the DRS4 Switched Capacitor Array Chip,[2] as primary author of the MIDAS Data Acquisition System and as author of the ELOG Electronic Logbook.

He is co-author of two patents related to Switched Capacitor Array Circuits and their calibration.

In addition Ritt is an active member of the IEEE Nuclear and Plasma Sciences Society,[3] where he is a Distinguished Lecturer[4] and was Society President 2017-2018.