This case-control study aimed to explore sleep patterns, issues, and disorders in adolescents with persistent attention-deficit/hyperactivity disorder (ADHD) and those with partially remitted ADHD symptoms. The study included 281 participants diagnosed with ADHD (145 with persistent ADHD, 136 with subthreshold ADHD) and 185 unaffected control subjects. Psychiatric interviews and assessments were conducted using standardized tools, revealing that adolescents with a history of childhood ADHD diagnosis were more likely to experience current and lifetime sleep problems and disorders, such as insomnia, sleep terrors, nightmares, bruxism, and snoring. The presence of psychiatric comorbidities increased the risk of certain sleep problems. The study did not find a connection between sleep schedule disruption and ADHD but highlighted the importance of screening for sleep problems and psychiatric comorbidities in adolescents with a history of ADHD.