Suicide is a leading cause of mortality and firearm suicide accounts for the majority of fatalities. Firearm owners are a diverse population and firearm-specific suicide prevention programs should be tailored to distinct at-risk firearm-owning groups. This study set out to identify groups of firearm owners with differential suicide risk having unique characteristics that could be used to customize suicide prevention efforts. We conducted a nationally-representative survey of 2646 firearm owners to assess individual suicide risk, suicide risk factors, and demographic characteristics. A Latent Class Analysis identified unique segments of firearm owners at increased risk of suicide with similar underlying suicide risk factors and demographic characteristics. We found almost one in ten (9.6%) of firearm owners were at increased risk of suicide with 25% reporting suicide ideation, 6.6% reporting suicide planning, and 1.8% reporting previous suicide attempts. We identified three unique groups of firearm owners with higher than average suicide risk. Relative to other groups of firearm owners, one at-risk group were more affluent with a history of adverse experiences and mental health challenges, a second group had more male veterans with high levels of alcohol consumption, and third group had more non-heterosexual women who experienced trauma. We conclude that there are three unique groups of firearm owners with higher than average suicide risk with very different characteristics. In addition to broad suicide prevention efforts, customized firearm suicide prevention programs should be developed individually for these different firearm-owning populations, taking into consideration the unique suicide risk factors and demographics of each group.