Hubris is a dangerous cocktail of overconfidence, overambition, arrogance and pride fuelled by power and success. When found alongside contempt for the advice and criticism of others, hubris causes leaders to significantly overreach themselves, taking risky and reckless decisions with harmful, sometimes catastrophic consequences for themselves, their organisations, institutions, and even for society. Given the economic, social, and geopolitical damage that can ensue, we should learn to recognise the signs of how hubristic leaders talk and act, and how to mitigate the consequences.