Objective To identify and verify classes of firearm owners that exist within the United States and determine the sources that classes deemed credible to discuss firearm safety for suicide prevention. Methods The study is composed of two parts. Part 1 (N = 1018) utilizes a nationally representative sample of firearm owners. Part 2 (N = 1064) consists of firearm owners from Mississippi, Minnesota, and New Jersey. Results Four unique classes were identified in Sample 1: multiple firearms class, single handgun class, few firearms class, and long-gun class. A three-class solution was found for sample 2. Two of the classes from sample 1 replicated: multiple firearms class and single handgun class. Although many of the classes differed in the ranking of credible sources, a combination of The American Foundation for Suicide Prevention, law enforcement officers, and family members was ranked as credible sources among all classes. Conclusions Findings provide evidence of the heterogenous nature of firearm owners and can be utilized to better understand the subgroups of firearm owners. Additionally, the findings from the credible sources analyses can be leveraged to create more effective safe firearm storage messaging which may increase adherence with safe storage suggestions and ultimately reduce suicide rates.