The purpose of this study was to evaluate the prevalence and correlates of insomnia using rigorous diagnostic criteria and a comprehensive assessment battery. In a large sample (N=1,074) of college students (mean age 20.39. years), participants were asked to complete a week-long sleep diary and comprehensive questionnaire packet assessing recommended daytime functioning domains (i.e., fatigue, quality of life, depression, anxiety, stress, academic performance, substance use) during the academic year. A significant portion of this sample of college students met proposed DSM-5 criteria for chronic insomnia (9.5%). The chronic insomnia group reported significantly worse sleep, fatigue, depression, anxiety, stress, and quality of life, and greater hypnotic and stimulant use for sleep problems. There were no differences between groups on excessive daytime sleepiness, academic performance, or substance use. This was a rigorous and comprehensive assessment of the prevalence and psychosocial correlates of insomnia. Insomnia is a significant problem in college students and should be regularly assessed. More research is also needed to guide treatment in this population.