Blenduk Church, Protestant church in Old Town, Semarang, Indonesia.

Blenduk Church stands at 32 Letjen Suprapto Street in Semarang's Old Town, set in a small courtyard between former office buildings. The octagonal church has single-layer brick walls on a stone foundation, a large copper-skinned dome on 32 steel beams, and two square towers that round off toward small domes flanking the south entrance. Roman-style porticoes with saddle-shaped roofs cover the east, south and west faces.

Construction began in 1753 when Dutch settlers built this house of worship to serve their growing community in the port city. When a separate Catholic facility opened in Gedangan, the building became home to Protestant congregations alone.

The name Blenduk comes from the Javanese word mblenduk, meaning dome, referring to the copper-skinned roof added in the 1894 renovation. The church has served Protestants since 1753, and Catholics also worshipped here until the first Catholic church in Gedangan was built. A list of pastors from 1753 to the present is inscribed on the church walls.

This house of worship sits in the historic quarter and is accessible on foot, with parking available nearby for those arriving by car. Services take place on Sundays, so visitors should be respectful during active worship and dress appropriately when entering.

The spiral staircase to the gallery bears the name of its maker, Pletterij den Haag, a rolling mill in The Hague, showing the fittings were shipped from the Netherlands. The pulpit stands on an octagonal teak platform, and the floor is laid with black, yellow and white tiles.