Berwick is a town in St. Mary Parish, Louisiana, United States. The population was 4,946 at the 2010 census. It is part of the Morgan City Micropolitan Statistical Area.V.J. Bella, state representative from St. Mary Parish from 1972–1990, was known as a legislative fiscal watchdog. Prior to his legislative service, Bella was the fire chief in Berwick. He subsequently served as state fire marshal.Perhaps the most prominent person from Berwick is Jenny Craig, weight loss guru and founder of Jenny Craig, Inc.