Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases that control a diverse range of biological processes during development and in adult tissues. We recently reported that somatic FGFR2 mutations are associated with shorter survival in endometrial cancer (EC). However, little is known about how these FGFR2 mutations contribute to EC metastasis. Here, we report that expression of the activating mutations, FGFR2N550K and FGFR2Y376C, in an EC cell model induce Golgi fragmentation, and loss of polarity and directional migration. In mutant FGFR2-expressing cells, this was associated with an inability to polarise intracellular pools of FGFR2 towards the front of migrating cells. Such polarisation defects were exacerbated in 3-Dimensional culture where FGFR2 mutant cells were unable to form well-organized acini, instead undergoing exogenous ligand-independent invasion. Our findings uncover collective cell polarity and invasion as common targets of disease-associated FGFR2 mutations that lead to poor outcome in EC patients.