Objective: Attention deficit hyperactivity disorder (ADHD) negatively influences various aspects of life such as social relations, adaptive skills, and occupation. In addition, many university students experience sleep problems, academic failure, and low quality of life (QOL). We investigated the relationship among ADHD symptoms, sleep quality, and QOL of college students, and identified the factors related to their QOL. Participants and Methods: Using a survey questionnaire, data were collected from 195 students from March-May 2017. Results: QOL of students was related to ADHD symptoms and sleep quality. Factors significantly associated with better QOL were fewer ADHD symptoms, good sleep quality, male sex, high academic performance, and high economic status. The explanatory power of these variables on QOL was 32.0%. Conclusion: To improve the QOL of college students, a multifaceted approach that includes assessment of ADHD symptoms and sleep quality is needed.