The present studies assess similarities and differences between sport fans and other types of fans in terms of identification with the fan interest (fanship), identification with other fans (fandom), entitativity, and collective happiness. In Study 1, a unidimensional 11-item scale to measure degree of identification with a fan interest was constructed. In Study 2, convergent and divergent validity for the measure was examined. In Study 3, criterion validity was examined. In Study 4, fanship positively correlated with entitativity, identification with other fans, and collective happiness. Sport fans were found to be similar to fans of other interests. Fans perceived themselves to be in a group even when they are not actively part of an organized group. Fanship and fandom were found to be positively correlated yet distinct constructs.