Sibak (Persian: سيبك) is a village in, and the capital of, Cheshmeh Langan Rural District of the Central District of Fereydunshahr County, Isfahan province, Iran.

At the 2006 National Census, its population was 1,394 in 329 households. The following census in 2011 counted 1,354 people in 396 households. The latest census in 2016 showed a population of 1,290 people in 385 households. It was the most populous village in its rural district.

Language

The town is about 60% Georgian speaking, 30% Luri speaking and the rest being standard Farsi.