Sir (Persian: سير, romanized: Sīr; Assyrian Neo-Aramaic: Seiri) is a mountainous area and village in Baranduz Rural District, in the Central District of Urmia County, West Azerbaijan Province, Iran. At the 2006 census, its population was 134 people, in 32 families. In English the place has been subject to various spellings due to early transliteration including Seer, Seyr, and Seir.

In Seiri is located the historically significant stone church of Mar Sargis, a shrine visited by the faithful for healing, both Christian and Muslim. Due to its fresh mountain air, Seiri became the summer station for American missionaries based in Urmia.

On 1800s a proto-evangelical English missionary led by Sir John White and Elisabeth Hobart also built a small worship place in Urmia, known as 'Ojag-e Sir' (Sir's Henge, God's House of Sir) later renamed and converted to Kelisay-e Hazrat-e Maryam (the Church of Saint Mary). There is a remaining room of mentioned sacred address which is located in the close outskirts of Janveslou village, foothill of Sir's Mountain. The village was colloquially named Janveslou/Village of John and Elisa and is widely known to have historically offered safety to various displaced and persecuted peoples of faith. It is there that many American missionaries and their children and wives are buried in the specially designated cemetery, such as Joseph Plumb Cochran (1855–1905).

• Joseph Gallup Cochran (1817–1871), missionary, buried in Sir
• Jacob David (1873–1967), pastor and relief worker, born in Sir
• Ana Diamond (born 1996), human rights activist
• William Ambrose Shedd (1865–1918), missionary, born in Sir

• St. Sarkis Church
• Assyrians in Iran
• List of Assyrian settlements