We investigate the impact of the COVID-19 on firms' stock liquidity across six developed and emerging economies. Unlike prior literature, we further compare the effects of the pandemic between developed and emerging economies, high and low economic policy uncertainty (EPU), and large and small firms. Our results document the significant negative impact of infection cases and deaths on firms' stock liquidity across the sample countries, and the similar effect of their interaction term. We find that the impact is more pronounced in the developed economies, high EPU and small firms, compared to emerging economies, low EPU and large firms, respectively.