The purpose of this paper is to provide a critical review of extant knowledge on emoji use in Computer-Mediated Communication (CMC). A compilation of 46 empirical studies published between 1998 and 2020 are presented as a critical review and in a Summary Table that reports the methodology, sample, key findings, user status and context of use for each paper. The classification of findings is based on user status (i.e. individuals who use emojis vs. individuals who view emojis). Regarding emoji users, extant insights on emojis' functions, popularity and frequency of use, profile of emoji user and condition that favour their use are presented. Then, the effect on emojis in both personal and business contexts are presented. Finally, the paper aims at setting the future research agenda in the area of emoji use in CMC by highlighting areas where results are equivocal, areas with limited research attention and research issues that would enhance our academic knowledge and current business practice.