Teachers' innovative work behavior and professional development is receiving more attention lately. More precisely, it is argued that teachers' formal and informal learning is crucial to anticipate and deal with continuous changes and innovations in technology and didactics, for example. Therefore, this study researches the teachers' innovative work behavior by studying relations between (in)formal learning activities, employability (i.e. five competences: occupational expertise, anticipation and optimization, personal flexibility, corporate sense and balance) and innovative working behavior (IWB, i.e. ideas generation, promotion and realization). Furthermore, the mediating role of employability between learning and innovative working behavior is studied, too. Based on path analysis conducted on questionnaire data from 301 primary and secondary school teachers from the French-speaking community of Belgium, findings conclude that employability competences are related to both formal and informal learning, but the relationship between informal learning and employability is stronger. Next, making a distinction between the frequency and use of social informal learning is relevant given the differentiated role the different components play. Feedback use in particular seems to play an important role in teachers' employability and IWB. Finally, it can be concluded that employability partially mediates the relation between the undertaking of (in)formal learning activities and dimensions of innovative working behavior. Results imply that schools should pay more attention to supporting teachers' informal learning since it's crucial for improving their ability to innovate and to be able to deal with changes in the dynamic world of education.