Aims and objectives: This study examines fennicisms (i.e., Finnish loanwords and calques) in Finland-Swedish, a Swedish variety spoken in Finland. We investigate how fennicism frequency relates to speakers’ regional backgrounds and fluency in Finnish. Methodology: 134 participants from four regions in Finland performed a picture-naming task designed to elicit fennicisms. The participants also rated their own fluency in Finnish. Data and analysis: A regression analysis with the outcome variable of fennicism frequency and the predictors of region, fluency in Finnish, and gender was performed. Findings: Results show that speakers from the more bilingual regions of Southern Finland and Helsinki used significantly more fennicisms than speakers from Ostrobothnia or Swedish-speaking Åland. The study suggests that fluency in Finnish was a strong predictor for fennicism use, as speakers with low or moderate knowledge of Finnish used fewer fennicisms than speakers with high or native(-like) fluency. No significant effect of gender was found. Originality: While fennicisms are considered widespread in Finland-Swedish, there is little previous research on their use and distribution. Implications: The results demonstrate that while many of the fennicisms are well-established in the Finland-Swedish variety, their use is limited to certain groups and communities.