Objective: This study was aimed to determine excessive daytime sleepiness (EDS) and related factors in adults. Materials and Methods: This cross-sectional study was conducted in Çorum, an inland province in the Black Sea Region of Turkey, with 575 adults between the ages of 18 and 64 years who registered at a Family Health Center. In this study, a self-administered 37-item questionnaire and the Turkish version of the Epworth Sleepiness Scale were used. Results: In our study, the overall prevalence of excessive daytime sleepiness was 11.3%. It was significantly prevalent among adults under the age of 25 years with the increased risk being 1.18-fold. Furthermore, it was more prevalent among women. Increased risk of excessive daytime sleepiness was 3.05-fold higher in adults with chronic disease and 1.78-fold higher with adults having a stressful life. Among the sleep-related habits, it was more often in adults with “sleep speaking, restless sleep, breathing pauses, subjective sense of having a problem related with sleep, waking up feeling unrefreshed.” Conclusion: The results of our study showed that nearly one in ten adults was suffering from EDS. It is suggested that to improve sleep hygiene and to manage chronic disease for people with daytime sleepiness should be a priority for public health and preventive medicine practices.