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.

The Battle of Vasai or the Battle of Bassein was fought between the Marathas and the Portuguese rulers of Vasai, a town near Mumbai (Bombay) in the Konkan region of the present-day state of Maharashtra, India. The Marathas were led by Chimaji Appa, a brother of Peshwa Baji Rao I.