Masai <马西 / 吗哂> is a town located in east Johor Bahru District, Johor, Malaysia, and is the oldest part of Johor Bahru. It is located 25 kilometres from the Johor Bahru city centre. Masai is located on route J10 which leads to Kong Kong, a fishing village along Johor River. The main access roads to Masai are Jalan Masai Lama(J10) and Pasir Gudang Highway(Federal Route 17).
Many pre-war buildings are still well preserved. Masai, like many of the towns in the Johor Bahru district, catered to the rural population of farmers and rubber plantation workers throughout the early and mid 20th century.