From the Latin verb migrare, meaning ‘to move from one place to another’, migration is self-evidently a correlative of travel. Broadly speaking, the term denotes the journeys undertaken by humans, or other species, to live elsewhere either temporarily or permanently. Migration is also recognized as having had a singularly transformative influence on places, cultures and identities throughout human history. Within the field of travel writing and its study, the potential of migration to alter the frames of reference used for defining the genre is also considerable. Nonetheless, migration's competing meanings and critical uses mean that accounting for the journeys it encompasses is not straightforward. Caught between the liberating cultural contribution of the cosmopolitan migrant and the unsettling ‘fluidity of the masses’ that must be controlled (Urry 2000, 27), migration as concept and practice points to the open-ended development of travel writing at the same time as it signals the need to reject its givenness.

Migration understood as a transformative and ultimately enabling travel practice is evidenced most clearly in the widespread appeal of its metaphoricity within specific strands of critical discourse. In the later decades of the twentieth century, metaphorical uses of migration – and the recurrence of figures and tropes such as the nomad (see nomadism), the vagabond, exile, displacement, homelessness, borders – were increasingly used to conceptualize the emergent identities of a globalized world and the epistemic transformations of Western critical thought. A migrant intelligentsia that understood theorization as a product of its own mobility and displacement spearheaded much of this development. For example, Trinh T. Minh-Ha (1994, 9) argues that ‘the travelling self is both […] the self that moves physically from one place to another […] and the self that embarks on an undetermined journeying practice, having constantly to negotiate between home and abroad’. ‘Migrants’ are presented by Homi Bhabha (1990, 315) as part of the ‘wandering peoples who […] are the marks of a shifting boundary that alienates the frontiers of the modern nation [and] makes it unheimlich’. And Gloria Anzaldúa (1987) suggests that the borders negotiated by migrants are not just geographical spaces but embodied spaces that inflict unhealable wounds.

Although the enabling dual (at least) perspective of these cultural migrants has been welcomed as a challenge to fixed positions, it has also been questioned for its failure to differentiate sufficiently between the material and the metaphorical.