The Holy Trinity Cathedral of Tbilisi (Georgian: თბილისის წმინდა სამების საკათედრო ტაძარი ) commonly known as Sameba (Georgian: სამების ლავრა for Trinity) is the main cathedral of the Georgian Orthodox Church located in Tbilisi, the capital of Georgia. Constructed between 1995 and 2004, it is the third-tallest Eastern Orthodox cathedral in the world and one of the largest religious buildings in the world by total area. Sameba is a synthesis of traditional styles dominating the Georgian church architecture at various stages in history and has some Byzantine undertones.

The idea to build a new cathedral to commemorate 1,500 years of autocephaly of the Georgian Orthodox Church and 2,000 years from the birth of Jesus emerged as early as 1989, a crucial year for the national awakening of the then-Soviet republic of Georgia. In May 1989, the Georgian Orthodox Patriarchate and the authorities of Tbilisi announced an international contest for the “Holy Trinity Cathedral” project. No winner was chosen at the first round of the contest when more than a hundred projects were submitted. Finally the design by architect  Archil Mindiashvili  won. The subsequent turbulent years of civil unrest in Georgia deferred this grandiose plan for six years, and it was not until November 23, 1995, that the foundation of the new cathedral was laid.

The construction of the church was proclaimed as a “symbol of the Georgian national and spiritual revival” and was sponsored mostly by anonymous donations from several businessmen and common citizens. On November 23, 2004, on St. George’s Day, the cathedral was consecrated by Catholicos Patriarch of Georgia Ilia II and high-ranking representatives of fellow Orthodox Churches of the world. The ceremony was also attended by leaders of other religious and confessional communities in Georgia as well as by political leaders.

The Sameba Cathedral is erected on the Elia Hill, which rises above the left bank of the Kura River (Mtkvari) in the historic neighborhood of Avlabari in Old Tbilisi.

The cathedral consists of nine chapels (chapels of the ArchangelsJohn the BaptistSaint NinoSaint GeorgeSaint Nicholas, theTwelve Apostles, and All Saints); five of them are situated in a large, underground compartment. The overall area of the cathedral, including its large narthex, is 5,000 square meters and the volume it occupies is 137 cubic meters. The interior of the church measures 56 metres by 44 metres, with an interior area of 2,380 square metres. The height of the cathedral from the ground to the top of the cross is 105,5 metres. The underground chapel occupies 35,550 cubic metres. The height is 13 metres.

Natural materials are used for construction. The floor is made of marble tiles and the altar will also be decorated with mosaic. The painting of the murals is being executed by a group of artists guided by Amiran Goglidze.

The Sameba complex, the construction of which is already completed, consists of the main cathedral church, a free-standing bell-tower, the residence of the Patriarch, a monastery, a clerical seminary and theological academy, several workshops, places for rest, etc.