Holy Trinity Cathedral, Romanian Orthodox cathedral in Arad, Romania.

Holy Trinity Cathedral is an Orthodox church building featuring Byzantine architectural elements including a central dome and four corner towers. The structure displays intricate decorative patterns on both its exterior walls and interior surfaces throughout the main prayer hall.

The cornerstone was laid in November 1991 by Bishop Timotei, and work began in 1992 with ground consolidation and foundations. It was the first Orthodox cathedral begun in Romania after the 1989 Revolution. Construction lasted until 2006, and Patriarch Daniel inaugurated it on Saint Nicholas's feast in 2008.

The cathedral serves as a gathering place where the local community participates in religious services and observances tied to Orthodox traditions. Visitors can witness how faith shapes daily spiritual life through ceremonies and celebrations held throughout the year.

The interior is open to visitors who wish to attend services or explore the architectural design in person. Visitors should dress appropriately and be respectful of prayer times or ongoing ceremonies taking place within the space.

The cathedral's bells were cast at a foundry in Innsbruck, Austria, and installed in December 2003. The five bells weigh 4,050, 1,070, 745, 450 and 250 kg, a total of 6.56 tonnes. In 2006 four gilded crosses were mounted on the domes: three of 3.5 metres and one of 7.30 metres.