Fantasy football ("soccer" in North America, Australasia, and certain other countries) is a rapidly growing online game with over seven million individuals playing the Official Premier League version alone. Whilst there is an abundance of anecdotal evidence associating the game with mental health concerns, to date there has been no empirical research conducted in this field. This study aimed to address this by having fantasy football players (N = 1995) complete questionnaires measuring low mood, anxiety, functional impairment, and problematic behavior in relation to playing the game. Descriptive statistics revealed that only a minority of players experienced mental health concerns toward fantasy football; however, it was also found that individuals who engaged most in fantasy football (i.e., high time spent playing, researching, and thinking about the game) had significantly worse mental health scores toward the game than those who engaged less. Interestingly, experience in fantasy football showed the opposite effect. It may be that players of fantasy football establish coping mechanisms over time or develop an emotional numbness to the game. Future research should explore this, as well as investigate other factors (such as in-game success, social media use, and perceived locus of control) that may impact the feelings of low mood, anxiety, functional impairment, and problematic behavior that can exist when playing fantasy football.