Hasan Abad (Persian: Hasan Ābād – حسن‌آباد), also spelled Hasanabad, is an old and historical area within the Monirie District of Tehran, Iran. There is also a famous square in the area which carries the same name.

The area was originally developed during the reign of the Qajar dynasty.

Hasanabad Square was built by the order of Mirza Yusef Ashtiani, the vizier of Naser ed Din Shah, and was named after his son, Mirza Hasan Ashtiani, who then became the Prime Minister of Iran for a period.

Following the 1979 Revolution, the square was renamed to The 31st of Shahrivar, in commemoration of the invasion of Iraqi bombers to the Iranian air bases. However, the new name did not remain and it has been reverted to Hasan Abad.

Once there was a statue at the square, which represented the Qajar-era constitutional activist Malek ol Motekallemin. After the 1979 Revolution, for unspecified reasons, the statue was moved to the store of the City's Park and then completely disappeared.