Sleep disturbances are commonly reported in youth with chronic pain. We examined whether online cognitive-behavioral therapy (CBT) for pain management would impact youth's sleep. Subjective sleep quality and actigraphic sleep were evaluated in 33 youth (M = 14.8 years; 70% female) with chronic pain participating in a larger randomized controlled trial of online-CBT. The Internet treatment condition (n = 17) received 8-10 weeks of online-CBT + standard care, and the wait-list control condition (n = 16) continued with standard care. Although pain improved with online-CBT, no changes were observed in sleep outcomes. Shorter pretreatment sleep duration was associated with less improvement in posttreatment functioning. Findings underscore the need for further development in psychological therapies to more intensively target sleep loss in youth with chronic pain.