Vahman-Ardashir or Bahman-Ardashir, also known as Forat Meshan (also spelled as Mayshan, Maysan, Meshun and Maishan), was an ancient town and sub-district in the Sasanian province of Meshan, which is situated in present-day southern Iraq.
According to the two Persian historians Hamza Isfahani and Ibn al-Faqih, Vahman-Ardashir was constructed (or re-built) by the first king of the Sasanian Empire, Ardashir I (r. 224–242), while some other sources such as al-Tabari, gives the legendary Iranian king Kay Bahman credit for the foundation of the town.
However, mention of this town first appears in 544, when the Nestorian bishop of Vahman-Ardashir is appointed as the metropolitan of Meshan.
According to Ibn Khordadbeh, Vahman-Ardashir, along with Meshan (a sub-district named after the province), Dastimeshan, and Abar-Kavadh, formed the four sub-districts of a district named Shad Bahman (also spelled Vahman), which also known as "the Tigris district".
In 635, during the Muslim conquest of Persia, Vahman-Ardashir was seized by the Arab military officer Utbah ibn Ghazwan.