Dhamar (Arabic: ذمار‎ Ḏamār), also spelt Thamar, is a governorate of Yemen. It is located to the south and southeast of Sana'a Governorate, to the north of Ibb Governorate, to the east of Al Hudaydah Governorate and to the northwest of Al Bayda' Governorate in the central highlands of Yemen. It has a total areas of 7,586 km² (2,929 sq mi) and an estimated population of around one and a half million. The visitor enters Dhamar governorate about 70 km south of the Sana’a airport. The center of the governorate is about 100 km (62 mi) from Sana’a, the capital of the Republic. The governorate sits among a number of other governorates: Sana’a to the north and northeast, al-Bayda’ to the east, Ibb to the south, and Raymah and al-Hudaydah to the west.

The governorate covers 7,935 km² (3,064 sq mi), which is divided among 12 administrative districts (mudiriyyah) and further divided into 314 sub-districts (‘uzlah). According to the 2004 census, the governorate contains 1,329,229 people, most of whom live in the governorate’s 3,262 villages.