 This entry surveys several philosophical debates about the nature, scope, and value of our freedom to associate with other people in these different ways as well as our freedom to dissociate both from particular people and from people in general. Key questions concern, first, our degree of freedom to decide who is in and who is out: When may we refuse to associate with other people? When may we leave the associations we are in? When may we deny someone membership in our association? When may third-parties, such as the state, sever, compel, or intrude upon our associations? Second, key questions concern our degree of freedom to decide what to do as associates: What level of control should we have over the internal workings of our associations, especially if those workings harm either members or non-members? To what extent may we radically reshape, and thereby redefine, the associations we are in?