Affordances of Internet sites and Internet-based applications make personal information about romantic partners, friends, family members, and strangers easy to obtain. People use various techniques to find information about others, capitalizing on online affordances by using search engines to find relevant websites and databases; scouring the target’s social media or social networking site presence; accessing information about the target via their links or network association with others on social media; or asking questions or crowdsourcing information through online channels. Researchers have coined an assortment of terms to describe online social information seeking behaviors, such as interpersonal electronic surveillance, social surveillance, monitoring, patient-targeted Googling, cybervetting, websleuthing, human flesh search, lateral surveillance, Facebook surveillance, and Facebook stalking. Although considerable research has examined these behaviors, there has been little effort to clarify the concepts themselves. As a result, the literature is currently full of inconsistent and overlapping conceptualizations. To synthesize these concepts for future research, this review examines 73 online social information seeking concepts extracted from 186 articles. Specifically, the concepts are reviewed in light of their scope; the information seeker or target of information seeking (e.g., romantic partners, parents, children, employees, criminals); motives for information seeking (e.g., uncertainty, threat, curiosity); and the intensity of the behavior. Recommendations are provided for future research, such as employing clear conceptualizations and incorporating affordances. Finally, we offer a decision tree that researchers can use to help select appropriate terms to use in their work moving forward.