Marzban (in Persian: مرزبان‎, derived from marz مرز "border, boundary" and the suffix -bān بان "guardian") were a class of margraves or military commanders in charge of border provinces of the Sassanid Empire of Persia (Iran) between the 3rd and 7th centuries CE.

The modern Persian word marz is derived from Avestan marəza "frontier"; bān is cognate with Avestan and Old Persian pat "protector". The word was borrowed from New Persian into Arabic as marzubān (plural marāziba). Al-Marzubani has been used as a nisba (family title) for some Arabian families whose ancestor was a Marzban.

Marzbans were granted the administration of the border provinces and were responsible for maintaining the security of the trade routes, fighting the encroaching nomadic tribes such as Bedouin Arabs, White Huns and Oghuz Turks, and holding the first line of defense against settled enemies such as Romans and Kushans.

Sassanid Shahanshah (king of kings) usually selected Marzbans from Bozorgan, Persian noble families who held the most powerful positions in the imperial administration. The rank of Marzban, like most imperial administration, was mostly patrimonial, and was passed down through a single family for generations. Marzbans of greatest seniority were permitted a silver throne, while Marzbans of the most strategic border provinces, such as the province of Armenia, were allowed a golden throne. In military campaigns the regional Marzbans could be regarded as field marshals, while lesser spahbods could command a field army.