Service-learning (SL) contributes to systematically anchoring and expanding transfer activities of universities (Third Mission) and cooperation with external community partners in teaching and beyond. Accordingly, SL is considered the silver bullet of holistic education and is increasingly implemented in higher education institutions worldwide, regardless of subject disciplines. This paper illustrates the importance of SL as one of the strategies to fulfill the Third Mission at the Catholic Universities in Lublin (KUL), Poland, and in Eichstätt-Ingolstadt (KUEI), Germany, and shows potentials of this concept in the education of students of psychology, didactics and pedagogy. Based on examples of good practice from teaching formats of the three disciplines at KUL and KUEI, concepts and models of SL are outlined.