San Sebastian is one of the oldest churches of Toledo, Spain. It once was close to the former city gate called "Bab-al-Dabbagin" also known by its Spanish name as "Puerta de los Curtidores" (English translation: gate of the tanners). Archeological research shows that it was originally built as a mosque in the 10th century, and enlarged in the 11th century. The mosque was called Al-Dabbagin., sometimes transliterated as Adabaquín. Some time after 1085 it became the church of one of the six Toledan parishes of the Mozarabic rite. The architectural reconstruction dates from the late 12th or 13th century.
The church as it now remains shows the characteristics of the Mudéjar architectural style, with rich Arabic decorations. The tower of the church shows characteristics of the former minaret that stood in its place and is from the 15th century.