--- - |2+ Objective Recent research suggests that a gun owner social identity may undergird the deep political engagement of U.S. gun rights supporters. We adapt social psychological measures to assess whether such an identity does indeed exist, examine the factors that predict whether individuals hold the identity, and assess whether the identity predicts individuals’ political attitudes and participation. Methods We analyze two distinct survey data sets using various statistical techniques: (1) an original Mechanical Turk survey and (2) a survey of gun owners conducted by the Pew Research Center. Results Gun owner identity is an individual characteristic that can be meaningfully measured. Moreover, gun owner identity is predicted by contact with the National Rifle Association and participation in gun‐related social activities, among other factors. Further, this identity strongly predicts firearm‐related policy attitudes, the importance individuals place upon these issues, and their propensity to act in opposition to gun regulations, all independent of gun ownership. Conclusions Our results suggest that nuanced measurement of gun owner identity can provide a richer understanding of gun policy attitudes, identity politics, and interest group influence. In so doing, they help explain gun rights supporters’ unusual dedication and, by extension, the NRA's success in the realm of gun policy. - 'Social Science Quarterly, Volume 100, Issue 6, Page 2408-2424, October 2019. '