Zeyn ol Hajjilu () is a village in Shurakat-e Jonubi Rural District of Ilkhchi District in Osku County, East Azerbaijan province, Iran.
At the time of the 2006 National Census, the village's population was 1,443 in 357 households. The following census in 2011 counted 1,688 people in 498 households. The 2016 census measured the population of the village as 1,808 people in 546 households.