Chronic low back pain (LBP) shares a bidirectional relationship with sleep disturbance. Analgesics are often used for chronic LBP management however, the effects on sleep have not been thoroughly reviewed. This systematic review and meta-analysis assessed the effect of opioid and non-opioid medications on sleep in people with chronic LBP. Electronic databases were searched for randomized controlled trials which resulted in 16 eligible articles (14 studies). Sleep measures were secondary outcomes, with one study assessing sleep objectively and all other studies reporting subjective sleep. Twelve studies assessed opioid therapies whilst two studies examined non-opioid therapies. Eight studies (all opioid) were included in meta-analyses of sleep quality and sleep disturbance comparing opioid therapies with placebo-controls. Opioid therapies significantly improved sleep quality (SMD = 0.27, 95% CI: 0.17–0.36) and reduced sleep disturbance (SMD = 0.32, 95% CI: 0.25–0.40) compared to placebo-control. These findings show a clear improvement in subjective sleep associated with opioid therapies however, future studies should examine objective sleep outcomes which remain largely unexplored in chronic LBP. Addressing both pain and sleep together is important for effective management of comorbid conditions of chronic LBP and sleep disturbance due to their bidirectional relationship.