In response to the COVID-19 pandemic, countries are introducing digital passports that allow citizens to return to normal activities if they were previously infected with (immunity passport) or vaccinated against (vaccination passport) SARS-CoV-2. To be effective, policy decision makers must know whether immunity and vaccination passports will be widely accepted by the public, and under what conditions? We collected representative samples across six countries – Australia, Japan, Taiwan, Germany, Spain, and the United Kingdom – during the 2020 COVID-19 pandemic to assess attitudes towards the introduction of immunity passports. Immunity passport support was moderate-to-low, ranging from 51% in the UK and Germany, down to 22% in Japan. Bayesian generalized linear mixed effects modelling controlling for each country showed neoliberal world views, personal concern and perceived virus severity, the fairness of immunity passports, and willingness to become infected to gain an immunity passport, were all predictive factors of immunity passport support. By contrast, gender (woman), immunity passport concern, and risk of harm to society predicted a decrease in support for immunity passports. Minor differences in predictive factors were found between countries. These findings will help policy makers introduce effective immunity passport policies in these six countries and around the world.