Some American science fiction and fantasy (SF&F) female fans participate in Cosplay or costume play, the global practice of dressing in costume and performing fictional characters from popular culture. Cosplay is typically only socially sanctioned at conventions and other fan events, leaving fans searching for new ways to express their fandom in everyday life. Closet cosplay is one solution in which everyday clothing and accessories can be worn to express fandom. The motivations for wearing everyday fan fashion have been only briefly mentioned by other authors or studied within limited social contexts. Therefore, the purpose of this research was to explore SF&F female fans' participation in closet cosplay as it is worn in everyday contexts. An exploratory qualitative study was conducted using a social interactionist perspective, and Sarah Thornton's concept of subcultural capital and Pierre Bourdieu's theory of cultural capital. Semi-structured, online interviews were conducted with sixteen participants who wore closet cosplay related to SF&F films and/or television series, which included Star Wars, Marvel Comics, DC Comics, Disney films, Harry Potter and anime fandoms like Sailor Moon (1995‐2000). The interview data were analysed using NVivo qualitative analysis software and the constant comparison method. Two themes emerged from the data: the definition of closet cosplay and motivations for wearing closet cosplay. Through examining these themes, it was evident that female SF&F fans used closet cosplay to express a salient fan identity, which enabled them to simultaneously gain subcultural capital and feminized cultural capital.