This study examines the use of and attitudes towards finlandisms and fennicisms in Finland Swedish. Finlandisms are words or structures typical of the Swedish variety spoken in Finland, while fennicisms are a category of finlandisms for which the source language is Finnish. Fennicisms are often discussed in context of Finnish influence and consequent Finland Swedish language loss, suggesting that the use of these features in Swedish is stigmatised. The study analyses survey responses from 126 Finland Swedish individuals in order to investigate the use of and perceptions regarding fennicisms. The responses indicate that although finlandisms and, in particular, fennicisms are often seen as erroneous, they can also be used to indicate a uniquely Finland Swedish linguistic identity. Additionally, responses regarding fennicisms provide examples of previously overlooked Finnish loanwords, while also indicating that loanwords with origins in other languages are often misidentified as stemming from Finnish. The implications of these findings are discussed.