Babolsar (Persian: بابلسر, also Romanized as Bābolsar and Bābul Sar; also known as Mashhadsar (Persian: مَشهَدسَر), also Romanized as Mashhad-i-Sar and Meshed-i-Sar) is a city in and the capital of Babolsar County, Mazandaran Province, Iran. At the 2006 census, its population was 47,872, in 13,442 families.