Hagia Sophia is a museum open to the public, and visitors are generally expected to dress modestly and respectfully when visiting. This means avoiding revealing or inappropriate clothing, such as short skirts or tops that expose too much skin.

It is generally acceptable to wear a dress to Hagia Sophia as long as it is not too short or revealing. It is always a good idea to check the museum's website or with local authorities for any specific dress code guidelines that may be in place.

Generally, it is essential to dress modestly and respectfully when visiting cultural and religious sites, including museums like Hagia Sophia. This helps to show respect for the site and its cultural significance.