The Day of the Open Mosque (German: Tag der offenen Moschee) in Germany is an annually scheduled event day that has existed since 1997 and takes place on October 3, the Day of German Unity. On this day, the mosque communities offer the predominantly non-Muslim visitors mosque tours, panel discussions and book and art exhibitions. Folklore, tea, coffee and pastries are also often part of the social program.
According to the Central Council of Muslims in Germany, the date was deliberately chosen to highlight the goal of cross-religious understanding. It is also intended to express the Muslims' self-image of being part of the German state, which was reunified in 1990, and their solidarity with all non-Muslim inhabitants of Germany.
In 2021, the Open Mosque Day celebrated its 25th anniversary during the COVID-19 pandemic.