The National Sleep Foundation recommends that adolescents (age 14–17 years) sleep 8 to 10 hours per night. Sleep loss is associated with cognitive dysfunction, decreased reaction time, and poorer athletic performance. This study evaluated the effects of sleep on sports injury rate and academic and cognitive performance. Seventeen high school track and field athletes (7 males, 10 females, mean age 15.9 years) wore an actigraph device for 10 weeks and performed a computerized neurocognitive assessment. Overall, 900 nights of nocturnal sleep data were analysed. Total minutes in bed averaged 501 minutes (8 hours and 21 minutes) and total sleep time averaged 378 minutes (6 hours and 18 minutes). Statistically significant correlations were observed between mean total sleep time and age-adjusted scores for the neurocognitive domains of episodic memory (p = .03) and fluid cognition (p = .03). Sleep loss in student-athletes may result in greater cognitive difficulties and impair academic abilities in the classroom.