The relationship between political factors and health behaviours has been well-examined in recent years. Recent applications are found in the COVID-19 response of the United States, where political factors motivate the divide on healthcare policies and attitudes. The current study investigates the association between political partisanship and frequency of self-reported mask-wearing in Democrats and Republicans, where partisanship is defined as external orientation with a political party. Prior literature failed to disentangle the effects of partisanship from political ideology in health outcomes, and previous partisan trends are further incongruent with novel pandemic research on mask-wearing. This relationship between partisanship and health behaviour therefore requires scrutiny in light of the current pandemic, as partisanship may explain how such divides motivate COVID-19 perceptions in the public sphere. Secondary data analysis was carried out on 2807 participants’ responses to a large-scale survey on COVID-19 health behaviours. As aligned with previous literature, Democratic affiliation was associated with significant preference for reported mask-wearing, whereas Republican affiliation was linked to significant preference to report no mask-wearing. The current findings emphasize the extent to which polarized political affiliations are associated with uptake of mask-wearing in a US population, and finds comparison to similar research in the field. Current findings and literature implicate partisan-biased media and messaging in health behaviour uptake, with further applications to effective health policy with partisanship considerations. Potential further directions for the application of the current findings across culture and context are discussed.