Vasai-Virar is an agglomeration of four previously governed municipal councils: Vasai (Bassein), Virar, Nallasopara and Navghar-Manikpur, as well as a few towns to the east and west of the urban area. It lies in the Konkan division of Maharashtra, India.

Vasai is a historical place and city located in Palghar district; which was partitioned out of the Thana district in 2014. It also forms a part of Vasai-Virar twin cities in the Konkan division, Maharashtra, India, and comes under the Police Jurisdiction of Mira-Bhayander, Vasai-Virar Police Commissionerate.