Investigating the multi-layered mobility of Southeast Asian irregular farm workers in rural Taiwan, this article examines the formation of their mobility in a physical, geographical, occupational and socio-economic sense. Focusing on frequent movement in these four aspects, this article coins the term ‘fettered mobility’ for workers’ constant relocation in the villages’ informal farm labour market. In tandem with the focus of this Special Issue on the ongoing transformations of migration at the crossroad between the legal, social and economic obstacles dictated by nation states and the market, and new patterns of movement, this article shows how ‘fettered mobility’ is an unintentional result of the Taiwanese state’s mobility regime, which regulates foreign nationals’ mobility by categorizing a hierarchical legal status. Fettered mobility is facilitated by the translocal migrant community constituted by the co-ethnic link between migrant workers and migrant spouse farmers, and also by the inter-ethnic link between the migrant community on the one hand and Taiwanese farmers and unlicensed brokers on the other. When migration is reconfiguring at a global, regional and local scale, fettered mobility is an assemblage in which the state, market and individual amalgamate into a networked, mobile, irregular and precarious labour force in which unprotected migrant workers are vulnerable to the state’s power to repatriate. Repatriation is an omnipresent threat, and anyone who knows of a migrant worker’s fettered mobility can put an end to their migration. Presenting fettered mobility as an assemblage, this article enriches the ongoing debate on the relationship between mobility and immobility and underlines its conditionality and instability.