Conspiracy theories tend to thrive in moments of crises because they provide simple answers that assist individuals in coping with threats, making the world more understandable. The COVID-19 pandemic is such a crisis and is boosted by the political turmoil related to politicization of the pandemic in some countries. To assess the role of political partisanship, conspiracy beliefs, and intolerance of uncertainty (IU) in our two criterion variables (support for COVID-19 prevention measures and compliance with social distancing), we applied an online questionnaire to 662 participants. We have used regression analyses to examine the data collected. Our results indicate that political partisanship predicts conspiracy theories involving personal wellbeing (PW) and control of information (CI) but not government malfeasance (GM) ones. Political partisanship predicted support to COVID-19 prevention measures while intolerance of uncertainty predicted past compliance with social distancing. Beliefs in GM theories predicted support to COVID-19 prevention measures and non-compliance with social distancing while beliefs in PW and CI only predicted non-compliance with social distancing. Belief in GM, PW, and CI theories moderated the effect of political partisanship on support to COVID-19 prevention measures whereas belief in GM and PW theories moderated the effect of IU on past non-compliance with social distancing. Overall, our results suggest the relevance of diminishing political polarization around the virus, providing basic scientific knowledge to the general population to make it easier to identify fake data and conspiracy theories, and offering psychological support focused on dealing with uncertainty to assist in increasing endorsement of and compliance with prevention measures.