The Cathedral of the Virgin Mary, Queen of the Holy Rosary (Indonesian: Gereja Katedral Perawan Maria Ratu Rosario Suci), also known as the Holy Rosary Cathedral or Randusari Cathedral is a Roman Catholic cathedral and the seat of the Archdiocese of Semarang. Finished in 1927 at Randusari, Semarang, Indonesia, it became a parish church in 1930 and a cathedral in 1940, when Albertus Soegijapranata was made the first apostolic vicar of Semarang.
The cathedral is located near Tugu Muda, in Randusari, Semarang. The Tugu Muda area, a Cultural Property of Indonesia, also includes Lawang Sewu, Mandala Bhakti Museum, and Bulu Market.
The cathedral complex includes the cathedral proper, a meeting hall, and school. In 2012 an official residence and office for the bishop was formalised. It contains a chapel, archive, secretariat, a garden, and general purpose room, as well as six rooms of residential space. It is the seat of the Archdiocese of Semarang.
The cathedral is built on a stone foundation, with a large, column-free congregation hall within. The roofs and arches have parapets, and the doors on the rectangular building face north, west, and south; the facade is to the west.