Siab-e Darvish (Persian: سيابدرويش, also Romanized as Sīāb-e Darvīsh; also known as Sīāb and Sīyāb) is a village in Gachi Rural District, Gachi District, Malekshahi County, Ilam Province, Iran. At the 2006 census, its population was 94, in 15 families. The village is populated by Kurds.