Hoo Fort is a nineteenth-century military installation on the River Medway in Kent, England, that formed part of the defences of Chatham Naval Dockyard.

It is located on Hoo Island covering Pinup Reach, the inner navigable channel of the River Medway.

The fort can be viewed from along the Saxon Shore Way, accessible from Vicarage Lane in Hoo.

[2] Each gun was mounted in an individual casemate with heavily armoured firing port.

In the Second World War, the fort was used as an observation post, with platforms and pillboxes built on top.