The effectiveness of measures introduced to minimise the spread of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2 or COVID-19) depends on compliance from all members of society. The Irish response to COVID-19 has been framed as a collective effort, fostering national solidarity. However, dominant representations of the national community often unreflexively reaffirm the prototypicality of majority group members, implicitly marginalizing minority group members. This may have implications for adherence behaviours. We propose that majority/minority membership of the national community predicts adherence to COVID-19 health advice via prototypicality and national solidarity. In Study 1, we collected data online from Irish residents (N = 1,185) during the first wave of restrictions in Ireland’s response. In Study 2, we collected data from Irish residents (N = 537) during the second wave of restrictions, with more targeted sampling of minority groups. Based on these two studies, there is no difference between minority and majority group members’ adherence behaviours. However, mediation analysis showed that greater adherence to COVID-19 health advice is shown when group members perceive themselves to be prototypical of the Irish national community, and thereby show greater national solidarity. In Study 3, we manipulated an appeal to adhere to restrictions (N = 689) and show that an inclusive solidarity appeal increased reported intentions to adhere to COVID-19 restrictions compared to an exclusive solidarity appeal among minority group members. These findings suggest that appeals to national solidarity in response to COVID-19 will be most successful when they reference the diversity of the nation.