"Protestant Church in Western Indonesia Immanuel Semarang" (Gereja Protestan Indonesia Barat Immanuel Semarang), better known as Blenduk Church (Gereja Blenduk) is a Protestant church at 32 Letjen Suprapto Street in the old town of Semarang, Central Java, Indonesia. Built in 1753, it is the oldest Christian church in the province.