Sophene (Armenian: Ծոփք Copʿkʿ, Ancient Greek: Σωφηνή Sōphēnē or Armenian: Չորրորդ Հայք, English: Fourth Armenia) was a province of the Armenian Kingdom and of the Roman Empire, located in the south-west of the kingdom. It currently lies in modern-day southeastern Turkey.

The region that was to become Sophene was part of the kingdom of Ararat (Urartu) in the 8th-7th centuries BC. After unifying the region with his kingdom in the early 700s BC, king Argishtis I of Urartu resettled many of its inhabitants to his newly built city of Erebuni (modern day Armenian capital Yerevan). Around 600 BC, Sophene became part of the newly emerged ancient Armenian Kingdom of the Orontids.

According to Anania Shirakatsi's Ashkharatsuyts ("World Atlas," 7th century), Tsopk (Sophene) was the 2nd among the 15 provinces of Greater Armenia. It consisted of 8 cantons (gavars):

After Alexander the Great's campaigns in 330s BC and the subsequent collapse of the Achaemenid Empire, Sophene remained part of the newly independent kingdom of Greater Armenia. In the early 200s BC, at the instigation of the Seleucid Empire, which was trying to weaken the Armenian kingdom, Sophene, split from Greater Armenia, forming the Kingdom of Sophene. The kingdom was ruled by a branch of the Armenian royal dynasty of Orontids. Sophene later split from the Sophene-Commagene kingdom as well, forming an independent kingdom. Commagene was part of Sophene at this time.