Objective: A crucial question regarding the public health impacts of cannabis legalization is its impact on alcohol consumption and alcohol-related harm. However, little is known about whether these changing cannabis policies are occurring in liberal or in restrictive alcohol policy environments, either of which likely affect public health outcomes. We constructed comprehensive state-level alcohol and cannabis policy indices and explored relationships between them., Method: We assessed relationships between the Alcohol Policy Scale (APS) and the Cannabis Policy Scale (CPS) from 1999 to 2019. The APS and CPS were based on 29 and 17 state-level policies, respectively, and each policy was weighted for its relative efficacy and degree of state-year implementation., Results: From 1999 to 2019, average state APS scores increased modestly (became more restrictive) by 4.11 points (2019 M = 43.23, range: 24.44-66.31) and average CPS scores decreased (became less restrictive) by 15.33 points (2019 M = 76.40, range: 29.40-95.74) on a 100-point scale. In 2019, average APS scores were similar among states that prohibited (criminalized) possession of cannabis (42.00), decriminalized possession (41.33), legalized medical cannabis (44.36), and legalized recreational cannabis (43.32). Across states, there was no correlation between the restrictiveness of state-level alcohol and cannabis policies ( r = .03, p = .37) in unadjusted models, although there was some variation by time, geographic region, and political party, with a weak negative correlation in state fixed-effects models., Conclusions: Although cannabis policies liberalized rapidly from 1999 to 2019, alcohol policies stayed relatively stable and did not differ by degree of cannabis policy liberalization. In general, there were weak associations between cannabis and alcohol policies among states; however, there was some temporal, regional, and political variation.