High Halstow is a village and civil parish on the Hoo Peninsula in the unitary authority of Medway in South East England. It was, until 1998, part of Kent and is still ceremonially associated via the Lieutenancies Act. The parish had a population of 1,781 according to the 2001 census, increasing to 1,807 at the 2011 census.Originally known as Hagelstowe (in Textus Roffensis), Hagelsto or Agelstow, it was named from an Old English word denoting a high, holy place.