Abstract This study extends the line of linguistic relativity research by assessing the effect of the French grammatical gender system on French speakers' and learners' perception of objects. Four groups of 140 adults (English monolinguals, French monolinguals, English–French bilinguals and French–English bilinguals; N = 35 each) rated 32 selected objects' gender by assigning them a masculine/feminine voice on a slider. We also assessed the participants' second-language (L2) proficiency. Multilevel modelling results revealed that French monolinguals and English–French bilinguals rated objects' gender in line with the French grammatical gender system. The effect of French on perception was not reduced by acquiring English, as French–English bilinguals performed on par with French monolinguals. Moreover, the effect was independent of L2 proficiency. These findings suggest that learning a gendered L2 affects the perception of objects – thus supporting the linguistic relativity hypothesis.