A community of interest, or interest-based community, is a community of people who share a common interest or passion. These people exchange ideas and thoughts about the given passion, but may know (or care) little about each other outside this area. Participation in a community of interest can be compelling, entertaining and create a community where people return frequently and remain for extended periods. Frequently, they cannot be easily defined by a particular geographical area.

In other words, "a community of interest is a gathering of people assembled around a topic of common interest. Its members take part in the community to exchange information, to obtain answers to personal questions or problems, to improve their understanding of a subject, to share common passions or to play."^[1] In contrast to a spatial community, "a 'community of interest' is defined not by space, but by some common bond (e.g. feeling of attachment) or entity (e.g. farming, church group)."^[2]

"Online communities" connect to communities of interest in that often, they develop out of interests in a particular topic.^[3] A benefit of online communities over place-based communities is that of non-physical access to group involvement.^[3]