Tolerance is outlined as willingness to accept characteristics of humans, behaviour, or beliefs and attitudes that are different from one’s own, although one might not agree with them or disapprove them. In education, different theoretical perspectives and methodological approaches can be taken that address different meanings of the concept. An overview is presented, and it is discussed in more detail how research on expertise can help to overcome ethical challenges that are related to issues of tolerance. Examples from a series of empirical studies are provided.