According to social facilitation theory the presence of others affects individuals’ sporting performance. Although based on extensive research, the theory has been scarcely tested in real sporting environments. However, audience restrictions due to the COVID-19 pandemic offered rare opportunities to examine effects of spectators’ presence and absence on football players’ performances. To exploit these opportunities, we collected data on individual players’ performances in the English Premier League (47,541 player performances in matches from the start of the 2017/18 season to 23rd January 2022) and Swedish Allsvenskan (25,249 performances in the 2018-2021 seasons). Results show that players’ performances were significantly better in the presence than in the absence of an audience (and the effect of audience presence was moderated by playing home or away) in the Premier League, but not Allsvenskan. Conversely, the effect of audience presence was moderated by average attendance and average stadium filling in and the relative skill of the opponent in Allsvenskan, but not the Premier League. The differences in results could be at least partly due to contextual differences between the two leagues, particularly in the average quality of players (which is higher in the Premier League). The study extends understanding of the complex nature of social facilitation in football, and highlights needs for further rigorous investigation of the mechanisms underlying the detected effects.