Background Children with attention‐deficit/hyperactivity disorder (ADHD) experience greater sleep problems than their peers. Although adolescence is generally a developmental period characterized by insufficient sleep, few studies have used a multi‐informant, multi‐method design, to examine whether sleep differs in adolescents with and without ADHD. Methods Targeted recruitment was used to enroll an approximately equal number of eighth‐grade adolescents (mean age = 13 years) with (n = 162) and without ADHD (n = 140). Adolescents and parents completed global ratings of sleep problems; adolescents, parents, and teachers completed ratings of daytime sleepiness. Adolescents wore actigraphs and completed a daily sleep diary for approximately 2 weeks. Results Adolescents with ADHD were more likely than adolescents without ADHD to obtain insufficient sleep on school days (per diary) and weekends (per diary and actigraphy). Adolescents with ADHD were also more likely to report falling asleep in class and to have stayed up all night at least twice in the previous 2 weeks (14% and 5% reported all‐nighters for ADHD and comparison, respectively). In regression analyses controlling for a number of variables known to impact sleep (e.g. pubertal development, sex, medication use, having an externalizing, anxiety, or depression diagnosis), ADHD remained associated with shorter diary and actigraphy school night sleep duration, adolescent‐ and parent‐reported daytime sleepiness, and parent‐reported difficulties initiating and maintaining sleep and total sleep disturbance. Controlling for other variables, the odds of being classified with clinically elevated parent‐reported sleep disturbance were 6.20 times greater for adolescents with ADHD. Conclusions Findings provide some of the clearest evidence yet that adolescents with ADHD experience more sleep problems and sleepiness than their peers without ADHD. It may be especially important to assess for sleep problems in adolescents with ADHD and to evaluate whether existing sleep interventions are effective, or can be optimized, for use in adolescents with ADHD who also have sleep problems.