Stationary‐to‐migratory transitions of epithelial cells have a key role in development and tumour progression. Border cell migration is a powerful system in which to investigate this transition in living organisms. Here, we identify the Ste20‐like kinase misshapen (msn) as a novel regulator of border‐cell migration in Drosophila. Expression of msn in border cells is independent of the transcription factor slow border cells and of inputs from all pathways that are known to control border‐cell migration. The msn gene functions to modulate the levels and/or distribution of Drosophila E‐cadherin to promote the invasive migratory behaviour of border cells.