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. The land on which the cathedral now stands belonged to the city's health department, but was purchased by the Catholic Church in 1926 to establish a new church to cater for the increasing number of Catholics in the area.