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". A estuary named Bahmanshir, is known to be derived from the name of Vahman-Ardashir.
In 635, during the Muslim conquest of Persia, Vahman-Ardashir was seized by the Arab military officer Utbah ibn Ghazwan. The town would later be involved in revolts by the Zanj in 689-690, 695, and during the height of the power of the Zanj, known as the Zanj Rebellion, which lasted from 869 to 883. During the 13th-century, Vahman-Ardashir was destroyed.