While the contribution of skilled immigrant workers to innovation has been well documented in many countries, there is still lack of evidence for France. We show that, when innovation is measured by the number of patents filed by firms, an increase of one percentage point in the share of skilled immigrant workforce in a French department allows firms in that department to file 5.2% more patents. This phenomenon is explained by a reallocation of native workers across different tasks rather than a replacement of national workers by immigrants. This result provides an additional argument for France to make progress on a skilled immigration policy.