Following considerable social and demographic change over the past six decades, macro-social theories have attempted to explain contemporary society through trends of weakening traditional institutions (e.g. state, church and family) and certainties (e.g. life-long full-time work and marriage) and growing self-articulation, individualisation, destandardisation and uncertainty. At the same time, new theories and discourses on population movement have emerged, in which emphasis is placed on mobility as both an empowering personal choice and a dominant process of modernity. The contemporary ubiquity of separation, and the corresponding rise of single-person and lone-parent households, is often proposed as one of the clearest articulations of instability, individualisation and weakening of the family. However, through regression-based modelling of geocoded British Household Panel Survey data, we use the compelling case of moves related to separation among families to demonstrate how: (1) links between related individuals can simultaneously trigger, shape and constrain (im)mobility; (2) linked lives can intersect in important ways with social, institutional and geographical structures; and (3) linked post-separation (im)mobility outcomes can often contradict individually-stated pre-separation preferences. Controlling for a range of multilevel characteristics, we find significant gender distinctions, with fathers more likely to leave the family home than mothers, and mothers less likely to break with post-separation familial proximity than fathers. Structural factors including housing-market geographies and population density are found to further shape these (im)mobility patterns. Together, our empirical analysis suggests that family dissolution will rarely herald a period of heightened individualisation, self-determination and unencumbered mobility. Indeed, a wider appreciation of the rise of non-traditional households, their complex linked lives and associated constraints could contribute to more realistic ...