As there are many conflicting sources of e-cigarette information, research is needed to determine the impact of these sources on e-cigarette attitudes to inform future communication campaigns. Source credibility is important in shaping attitudes toward other health topics; however, no study has examined its role in influencing e-cigarette attitudes. Data from the 2015 Health Information National Trends Survey-FDA (HINTS-FDA) were utilized to assess differences in trust in different sources by e-cigarette user status and to investigate the associations between trust in sources and e-cigarette attitudes (n = 3,738). Differences in trust in sources were examined using weighted linear regression. Associations between trust in sources of e-cigarette health effects and attitudes toward e-cigarettes were assessed using weighted logistic regression. Overall, e-cigarette ever users reported significantly lower trust in governmental agencies as compared to never users. Trust in e-cigarette companies was negatively associated with perceived addictiveness of e-cigarettes (AOR = 0.76, 95% CI = 0.58, 1.00), while trust in doctors/pharmacists/healthcare providers was negatively associated with harm perceptions of e-cigarettes relative to conventional cigarettes (AOR = 0.72, 95% CI = 0.55, 0.95). Trust in tobacco companies and trust in e-cigarette companies were negatively associated with absolute perceived harm of e-cigarettes (AOR = 0.70, 95% CI = 0.51, 0.95; AOR = 0.60, 95% CI = 0.46, 0.79, respectively). Results from this study indicate that the associations between trust in sources of e-cigarette health effects and e-cigarette attitudes differ both by source and specific attitude assessed. Ultimately, future campaigns should incorporate messaging to discredit industry sources of information and utilize non-governmental sources to effectively influence e-cigarette attitudes.