The aim of this study was to assess the association between state firearm legislation and female intimate partner homicide. In 2017, the authors conducted a secondary data analysis of 16 states from 2010 to 2014, using data from the National Violent Death Reporting System, the State Firearm Law Database, and additional public sources. Poisson regression analyses quantified the association between the number of state restrictive firearm legislative provisions and the female population-based intimate partner homicide rate. For etiologic reasons, intimate partner homicide was disaggregated into homicide-suicide (intimate partner homicide followed by perpetrator suicide) and homicide-only intimate partner homicide (intimate partner homicide in the absence of perpetrator suicide). There were 1,693 female intimate partner homicide deaths in the 16 states during 2010-2014; 67% were homicide-only intimate partner homicide. The number of state-level legislative provisions related to firearm restrictions ranged from four (Alaska) to 95 (Massachusetts). The intimate partner homicide rate in states with zero to 39 provisions was 1.16 per 100,000 person years (95% CI=1.10, 1.22) and in states with >40 provisions was 0.68 per 100,000 person years (95% CI=0.61, 0.72). The incidence of female intimate partner homicide was 56% lower in states with ≥40 legislative provisions (adjusted incidence rate ratio=0.44, 95% CI=0.28, 0.68), relative to states with zero to 39 provisions. This protective association was stronger for homicide-only intimate partner homicide than homicide-suicide intimate partner homicide. More state-level restrictive firearm legislation is associated with a lower rate of female intimate partner homicides.