Facing the rapidly ageing society and shrinking of markets at home, Japanese firms are expanding outbound mergers and acquisitions (M&A) activity at a record pace. This study examines the determinants of Japanese cross‐border M&A activity focusing on the role of migrant networks in overcoming the informational barriers to such activity. Migrants include immigrants residing in Japan as well as Japanese citizens residing abroad. Our results suggest that the presence of immigrants and of Japanese citizens residing abroad both increase the probability of acquiring assets in a potential target country. Moreover, both communities exert positive effects on the number and value of outbound M&A deals.