This chapter addresses the relationship between convention and ritual, and also provides an overview of these phenomena and the related research. In the technical literature convention and ritual are often merged together, or at least they are not sufficiently distinguished. This is not surprising, given these phenomena share a number of characteristics, as well as the fact that they jointly represent a key aspect of politeness, namely, recurrent behaviour, which is different from idiosyncratic forms of interaction (even though, as we argue, conventions and rituals can also be present in ad hoc, freely co-constructed forms of interaction). Yet, convention and ritual have a number of clearly different characteristics, and also address different interactional needs. Consequently, this chapter argues that it is essential to map the differences between these phenomena.