BACKGROUND: Given the sensitive nature of COVID-19 beliefs, evaluating them explicitly and implicitly may provide a fuller picture of how these beliefs vary based on identities and how they relate to mental health. OBJECTIVE: Three novel brief implicit association tests (BIATs) were created and evaluated: two that measured COVID-19-as-dangerous (vs. safe) and one that measured COVID-19 precautions-as-necessary (vs. unnecessary). Implicit and explicit COVID-19 associations were examined based on individuals demographic characteristics. Implicit associations were hypothesized to uniquely contribute to individuals self-reports of mental health. METHODS: Participants (N = 13,413 US residents; April-November 2020) were volunteers for a COVID-19 study. Participants completed one BIAT and self-report measures. This was a preregistered study with a planned internal replication. RESULTS: Results revealed older age was weakly associated with stronger implicit and explicit associations of COVID-as-dangerous and precautions-as-necessary. Black and Asian individuals reported greater necessity of taking precautions than White individuals (with small-to-medium effects); greater education was associated with greater explicit reports of COVID-19-as-dangerous and precautions-as-necessary with small effects. Replicated relationships between COVID-as-dangerous explicit associations and mental health had very small effects. CONCLUSIONS: Implicit associations did not predict mental health but there was evidence that stronger COVID-19-as-dangerous explicit associations are weakly associated with worse mental health.