Introduction and aims: Health literacy refers to the degree to which people can access and understand health information, as well as communicate their health needs to service providers. Whilst health literacy is increasingly being examined within general community samples, there is limited research focused on substance use disorders where the need for health literacy is likely to be high. The aim of this study was to examine the health literacy profiles of people attending substance use disorder treatment and to examine how these profiles were related to measures of quality of life, mental health, and physical health. Design and methods: Participants were attending specialist non-government substance use disorder treatment across New South Wales, Queensland, and the Australia Capital Territory, Australia (N = 298). Participants completed the Health Literacy Questionnaire, a multi-dimensional measure of health literacy. Latent profile analysis was conducted to identify profiles of health literacy within the sample. Results: Three distinct health literacy profiles were identified, and termed low (24.2%), moderate (62.8%) and high health literacy (13.1%). Participants with lower levels of health literacy had lower levels of social support in their home environment outside of treatment, as well as lower levels of quality of life, higher levels of psychological distress, and poorer mental health. There was no difference between the three profiles on measures of physical health. Discussion and conclusion: The current study found that low to moderate health literacy levels were common for those attending residential substance abuse treatment. Participants with lower health literacy tended to have poorer quality of life and mental health. Future research should examine strategies to improve health literacy amongst people attending alcohol and other drug treatment. It may also be useful for service providers to consider ways to minimise the impact of low health literacy on the health needs and outcomes of this vulnerable population.