Socioeconomic differences in sleep and how sleep relates to health and risky behaviors among 12‐ to 18‐year‐old Ghanaians (N = 1,195) were investigated. Overall, 49.2% of boys and 60.8% of girls had inadequate sleep. Girls (OR = 1.6, 95% CI = 1.3–2.0) and older (16‐ to 18‐year‐olds) adolescents (OR = 1.6, 95% CI = 1.3–2.1) had higher probability of inadequate sleep than boys and younger (12‐ to 15‐year‐old) adolescents, respectively. High material affluence, low parental education, low parental occupational grade, drunkenness, marijuana use, drug use, and not having plans to continue schooling after graduation decreased the chances of inadequate sleep, while low school performance, low fruit and vegetable intake, and tiredness during daytime increased the probability of inadequate sleep. Promotion of adequate sleep and gender equality should be taken into consideration in adolescent health promotion programs.