Introduction: Between 2017 and 2018 three major alcohol policy changes were introduced in the Northern Territory (NT): the Banned Drinker Register, an individual-level ban enforced via ID scanners at takeaway outlets; a Minimum Unit Price on alcohol; and Police Auxiliary Liquor Inspectors, who monitor takeaway outlets to prevent purchase by people who do not have a legal place to consume alcohol. We aimed to: (i) describe alcohol-involved adult sexual assault in the NT; and (ii) estimate the impacts of these alcohol policies on police-recorded adult sexual assault.

Methods: We used victim records for sexual assault where victims were aged 15 years and over. We undertook descriptive analyses for the NT from 2014 to 2020 and used interrupted time series analysis to assess policy impacts across the NT and in Greater Darwin.

Results: In 2020, the NT adult victimisation rate was 105 per 100,000. A large minority (40%) of adult sexual assaults involved alcohol. Interrupted time series analyses showed no effect of the Banned Drinker Register or Minimum Unit Price on sexual assault across the NT or in Greater Darwin.

Discussion and conclusions: The rate of adult sexual assaults in the NT is extremely high and many involve alcohol. Neither the Banned Drinker Register or Minimum Unit Price were associated with changes in police-recorded adult sexual assault in Greater Darwin or across the NT. Due to small counts, we were unable to assess policy impacts in three of the four main towns, highlighting the challenges of assessing impacts of policies on sexual assault in small population areas.