Abstract ‘Jamais vu’ is a strange mnemonic disturbance that we continue to experience today, though few of us know what to call it. French for ‘never seen,’ jamais vu is the opposite of déjà vu (‘already seen’), and is defined as the temporary inability to recognize familiar things, people, and/or contexts. This essay comprises, to my knowledge, the first literary history of jamais vu. I begin by describing the complex features of this mnemonic disturbance, and uncovering its lost Victorian scientific archive. Though jamais vu went without a name until the 1920s, I also find it hiding in plain sight in nineteenth-century novels as early as Jane Austen’s Mansfield Park, as well as in the work of Charles Dickens, William Makepeace Thackeray, George Eliot, and Elizabeth Gaskell. From here, I follow jamais vu’s trajectory from realist accounts of everyday life into mid-century representations of the haunted house, where it becomes something more than a mnemonic disturbance. By attending to literary representations of jamais vu avant la lettre, I demonstrate its importance not just as a lost Victorian scientific concept, but also as a rich interdisciplinary category that is of great interest to scholars of the nineteenth century and beyond. Specifically, I show that jamais vu was integral to the development and popularity of the Victorian gothic, through which movement it exceeded its status as a mnemonic disturbance, re-emerging as a pervasive modern affect that we have inherited from the Victorians.