Whittlesey is a market town and civil parish in the Fenland district of Cambridgeshire, England. Whittlesey is 6 miles east of Peterborough…Whittlesey is a market town and civil parish in the Fenland district of Cambridgeshire, England. Whittlesey is 6 miles east of Peterborough. The population of the parish was 17,667 at the 2021 Census.