Sanjabad-e Jonubi Rural District (Persian: دهستان سنجبد جنوبي) is in Firuz District of Kowsar County, Ardabil province, Iran. Its capital is the village of Firuzabad.

At the census of 2006, its population was 3,211 in 690 households. There were 3,054 inhabitants in 797 households at the following census of 2011. In the most recent census of 2016, the population of the rural district was 2,395 in 691 households. The most populous of its 26 villages was Firuzabad, with 489 people.