While public health crises such as the coronavirus pandemic transcend national borders, practical efforts to combat them are often instantiated at the national level. Thus, national group identities may play key roles in shaping compliance with and support for preventative measures (e.g., hygiene and lockdowns). Using data from 25,159 participants across representative samples from 21 nations, we investigated how different modalities of ingroup identification (attachment and glorification) are linked with reactions to the coronavirus pandemic (compliance and support for lockdown restrictions). We also examined the extent to which the associations of attachment and glorification with responses to the coronavirus pandemic are mediated through trust in information about the coronavirus pandemic from scientific and government sources. Multilevel models suggested that attachment, but not glorification, was associated with increased trust in science and compliance with federal COVID-19 guidelines. However, while both attachment and glorification were associated with trust in government and support for lockdown restrictions, glorification was more strongly associated with trust in government information than attachment. These results suggest that both attachment and glorification can be useful for promoting public health, although glorification's role, while potentially stronger, is restricted to pathways through trust in government information.