Background: Sleep problems are common amongst people who use alcohol and other drugs, but treatment options are limited. This paper explores how people in residential treatment for alcohol and other drug problems perceived and described ‘non-problematic’ sleep to provide insights that might inform sleep interventions for this population. Methods: Qualitative interviews were conducted with 28 residents (19 women, 9 men; ages 24-83 years) in two residential drug and alcohol treatment centres in England during 2014/15. Interviews were audio-recorded, transcribed, and coded. Accounts of non-problematic sleep were then analysed inductively. Results: Non-problematic sleep comprised three linked components: i. personal sleep patterns and routines; ii. sleep perceptions; and iii. sleep metacognitions. Some participants reported they slept well; others described their sleep as problematic but improving. Participants believed that sleep improved naturally with residential treatment and abstinence, but perceptions of ‘good’ sleep varied greatly. Participants used a range of metacognitive strategies (e.g. downgrading the importance of sleep; adapting their sleeping patterns; and focusing on sleep quality alongside sleep quantity) to manage sleep problems and render them non-problematic. Conclusions: Metacognitive strategies that focus on changing perceptions of sleep can potentially inform sleep interventions for people with a history of alcohol and other drug use.