The Sioni Cathedral of the Dormition is a Georgian Orthodox cathedral in Tbilisi, the capital of Georgia. Following a medieval Georgian tradition of naming churches after particular places in the Holy Land, the Sioni Cathedral bears the name of Mount Zion at Jerusalem. It is commonly known as the "Tbilisi Sioni" to distinguish it from several other churches across Georgia bearing the name Sioni.

Prince Grigory Grigorievich Gagarin was a Russian painter, Major General and administrator.