Thullur mandal is one of the 57 mandals in Guntur district of the Indian state of Andhra Pradesh. It is under the administration of Guntur Revenue Division and the headquarters are located at Thullur. The mandal is situated on the banks of Krishna River, bounded by Amaravathi, Tadikonda, Tadepalle and Mangalagiri mandals. The mandal is also a part of the new capital city of Andhra Pradesh to be developed. 18 villages from the mandal fall under the jurisdiction of Andhra Pradesh Capital City.