This thesis is a critical study of British and American Gothic prose representations of madness and the madhouse. This focuses on historical changes in asylum practice from the mid-nineteenth to the early twenty-first century, specifically from 1846 to 2014. While Gothic scholarship generally regards madness as being identifiable within most works of the genre, few studies have attempted to explain why it is that the Gothic's fascination with madness has endured beyond its literary origins in the late eighteenth century. Surprisingly, no full-length critical study has yet historically documented the Gothic mode's longstanding preoccupation with the madhouse, especially given how numerous these encounters in Gothic fictions are. For this reason, the present study turns its attention exclusively towards the institutional figure of the madhouse: a territory where madness has already been labelled into existence. The object of this thesis is to demonstrate how the Gothic text is haunted by notions of madness, and how in turn, the madhouse is haunted by discourses of the Gothic. This reading - informed by hauntology - of the Gothic madhouse space argues that by 'gothicising' the medical institution, Gothic fictions appeal to a memory of what has come before and anticipates a future for madness in Western culture. For this reason, Gothic encounters with the madhouse (where madness is simultaneously present and absent) are knowingly engaged with critiquing, politicising, rejecting, or even ignoring, the historical discourses on madness with which they are contemporary. This also examines the genre's complicity and reciprocity in longstanding and prejudicial attitudes towards mental ill-health. Divided into five historical epochs, this thesis reads: the Sweeney Todd story The String of Pearls (1846); Mary Elizabeth Braddon's Lady Audley's Secret (1861-2); Bram Stoker's Dracula (1897); four tales from H.P. Lovecraft including 'The Tomb' (1917), 'Beyond the Wall of Sleep' (1919), The Case of Charles Dexter Ward (1927), and 'The Thing on the Doorstep' (1933); Robert Bloch's Psycho (1959); Ken Kesey's One Flew Over the Cuckoo's Nest (1962); Iain Banks' The Wasp Factory (1984); Michael Moorcock's Mother London (1988); Patrick McGrath's Spider (1990), Asylum (1991), 'Ground Zero' (2005) and Trauma (2007); Sarah Waters' Fingersmith (2002), and John Harwood's The Asylum (2014).