The Kingdom of Saudi Arabia is the second largest country in the Arabian Peninsula and ranks 61st out of 150 countries in terms of coffee consumption. Excessive coffee consumption is associated with the risk of adverse health outcomes. This study aimed to assess awareness of the effects of coffee consumption and its relationship with insomnia among the adult population in Jazan, Saudi Arabia. A cross-sectional study was conducted with 431 adults in the Jazan region. A self-administered questionnaire was distributed to the participants using an online survey. Data were analyzed using Statistical Program for the Social Sciences, Version 24.0. Of 431 participants, 377 (87.5%) consumed coffee. Females and married women consumed more coffee than their counterparts (91.3%, P < .01; 92.8%, P < .05; respectively), while students consumed coffee (85.2%) less than both the employed and unemployed (P < .05). The proportion of consumption increased from underweight (79.7%) to normal weight (88.5%), and as high as 91.3% among overweight/obese (P < .05). More than one-third of the participants (35.5%) preferred drinking coffee at coffee shops. The most preferred coffee was Arabic coffee (40%), and the major reason for drinking coffee was to change their mood (29.7%). More than half of the participants (54.5%) reported that coffee caused insomnia (P < .01). Awareness-raising initiatives for the negative effects of excessive coffee consumption are important. Longitudinal studies are required in the next stage of research to identify trends such as the motivations and profiles of Saudi coffee drinkers.