Since the 1990's, governmental and non-governmental organizations have adopted several measures to increase access to the opioid overdose reversal medication naloxone. These include the implementation of laws that increase layperson naloxone access and overdose-specific Good Samaritan laws that protect those reporting overdoses from criminal sanction. The association of these legal changes with overdose mortality and non-medical opioid use is unknown. We assess the relationship of (1) naloxone access laws and (2) overdose Good Samaritan laws with opioid-overdose mortality and non-medical opioid use in the United States.We used 2000-2014 National Vital Statistics System data, 2002-2014 National Survey on Drug Use and Health data, and primary datasets of the location and timing of naloxone access laws and overdose Good Samaritan laws.By 2014, 30 states had a naloxone access and/or Good Samaritan law. States with naloxone access laws or Good Samaritan laws had a 14% (p = 0.033) and 15% (p = 0.050) lower incidence of opioid-overdose mortality, respectively. Both law types exhibit differential association with opioid-overdose mortality by race and age. No significant relationships were observed between any of the examined laws and non-medical opioid use.Laws designed to increase layperson engagement in opioid-overdose reversal were associated with reduced opioid-overdose mortality. We found no evidence that these measures were associated with increased non-medical opioid use.