One of just four disease-specific global awareness days officially endorsed by the World Health Organization (WHO), World Hepatitis Day 2019 unites patient organisations, governments, medical professionals, civil society, industry and the general public to boost the global profile of viral hepatitis. Worldwide, 300 million people are living with viral hepatitis unaware. Without finding the un-diagnosed and linking them to care, millions will continue to suffer, and lives will be lost. On World Hepatitis Day, 28 July, we call on people from across the world to take action and raise awareness to find the “missing millions”.