Formby is a town in Merseyside. The area is a civil parish and within the Metropolitan Borough of Sefton in Merseyside, England. It has a population of approximately 25,000, measured at the 2011 Census as 22,419.Historically in Lancashire, three manors are recorded in the Domesday book under "Fornebei" as Halsall, Walton and Poynton. The town's early recorded industry points to cockle raking, and shrimp fishing (in addition to arable ventures) last through into the 19th century.