Mohammad-Ali Hosseini would in the coming days replace Hamid-Reza Asefi as Foreign Ministry spokesman, the report quoted an informed source as saying.
It said that Asefi would resign his post on September 15.
A separate report said that Asefi was being considered for appointment as Irans ambassador to the United Arab Emirates.
Hosseini currently heads the Evaluation and Supervision Department of the Foreign Ministry.