Siyannu (Arabic: سيانو) is a Syrian village in Jableh District in Latakia Governorate.

According to the Syria Central Bureau of Statistics (CBS), Siyannu had a population of 4,784 in the 2004 census.

[1] Siyannu, which was also known as Ušnatu,[2] was part of Ugarit, before having its independence and becoming a border region with Amrit during the reign of the Hittite King Muršili II.

[3] Siyannu/Shianu,[4] led by King Adunu Baal, took part in the Battle of Qarqar against the invading Assyrians.

[5] Nahr as-Sinn was also called "Siyannu" which marked the southern borders of Ugarit.