© 2019, Springer Nature B.V. Two recent tsunamis in Indonesia highlight the importance of submarine landslides. Although both events had different origins (volcanic, seismic), submarine landsliding was probably the key component in tsunamigenesis. While a few recent submarine landslide-generated tsunamis have been discussed in the literature, these types of events have not been seriously scrutinised by geoscientists or hazard modellers. This is most likely because of both a lack of awareness and also the common perception that such events are too remote a possibility to be of major concern. However, by catching us off-guard, these two Indonesian events have brought slope-failure tsunamigenesis into sharper focus. It is hoped that this will stimulate greater scholarship on the issue of slope-failure tsunamigenesis worldwide, with an aim to better understanding event characteristics, probabilities, and ultimately better inform existing risk reduction strategies.