Imagine a neighborhood where young children can play freely in the streets and various backyards without direct parental oversight, the implication being that other adults in the vicinity will watch out for the children. If a parent is late getting home before the school bus, the children know which neighbors’ house to go to and will be well cared for until the parent arrives home. The residents are very willing to help each other, perhaps by moving a sofa down to a basement or lending a ladder for a project. In such a neighborhood, the first place one turns to for recommendations for plumbers, dry cleaners, and preschools, or perhaps to borrow a tool, is each other. Perhaps one person has secured a job for a neighbor’s daughter, and another family has “paved the way” for their neighbor’s entry into a country club. If a person has a need for emotional support to deal with a personal crisis, she turns to a neighbor. Such a neighborhood can be said to have social capital—that resource that comes from relations between people that makes lives more productive and easier. Social capital is not only created from groups of people living in very close proximity, such as in a neighborhood. It might be created between people belonging to the same church or civic group, or perhaps between people who met at a hospital support group for a particular affliction, or people who are alumni of a particular university. These groups of people can be said to constitute communities, or gatherings of people who have common interests or ties. In the past, these communities tended also to be focused in a local geographic area. This article will examine social capital in the context on online communities. Online communities, like physically based communities such as church groups or neighborhoods, can also be said to produce social capital for their members. These virtual communities can create and foster social capital—and indeed, it may be social capital that draws and retains their members. The background of social capital theory will be examined and then applied in the virtual community context.