BACKGROUND: Over 3 million Americans have an opioid use disorder (OUD), and only a fraction receive treatment. Public opinion is crucial in enacting evidence-based policies. Few studies have examined the public's perception of blame for the ongoing opioid overdose epidemic directed at distinct groups. We assessed US adults' perceived blameworthiness for the epidemic and examined factors that may influence the perceived blameworthiness. METHODS: We conducted a national survey in 2022 using the AmeriSpeak® panel to assess US adults' perception of blame toward individuals with an OUD and external contributors. Of the 3335 eligible panel members invited to participate, 1233 (37%) completed the survey. We developed a measure of knowledge and understanding of OUD, with a higher value indicating a greater understanding of the nature of OUD and recovery-including knowledge and beliefs on evidence-based treatment and relapse. We analyzed the relationships between sources of blame, knowledge, and understanding of OUD, and individual-level correlates. RESULTS: Higher score of knowledge and understanding of OUD was associated with lower odds of blaming individuals with OUD (odds ratio [OR] = 0.73, 95% confidence interval [CI] = [0.51, 1.05]) and greater odds of blaming external contributors: healthcare providers (OR = 1.49, 95% CI = [1.05, 2.12]), pharmaceutical companies (OR = 2.17, 95% CI = [1.50, 3.15]), and health insurance companies (OR = 1.42, 95% CI = [0.97, 2.09]). Those who are female, non-Hispanic White, Democrat, have higher education, or have friends or family who misused opioids tended to score higher in knowledge and understanding of OUD. CONCLUSIONS: Perceived blameworthiness for the opioid overdose epidemic is related to knowledge and understanding of OUD. Public health campaigns with a bipartisan agenda to increase evidence-informed knowledge about OUD targeting people of color and with lower education may help reduce the blame toward people with an OUD, which in turn may increase support for evidence-informed policies.