Iranian news agencies say the paper has been ordered to stop publishing from September 12.
"Sharq" had reportedly received 70 warnings for articles that were deemed insulting and for revealing information in defiance of demands by the Supreme National Security Council.
Iran's ILNA news agency reports that the paper's closure comes following the publication last week of an unspecified cartoon.
The newspaper's manager, Mehdi Rahmanian, said he will protest against the closure order.
The Iranian judiciary has closed dozens of independent and reformist publications in recent years.
The Paris-based Reporters Without Borders last week called on Iran to stop harassing the media.
(ILNA, IRNA, ISNA)