Domestic cats (Felis catus) are the most abundant predator in many urban ecosystems, and their ranging behaviour will influence predation rates. To investigate how degree of urbanisation affects cat ranging behaviour, we used Global Positioning System trackers to follow 38 cats in 3 (urban, suburban and peri-urban) residential areas in the large town of Reading, UK. Median home range (95% KE) was 1.28 ha, but varied from 0.9 ha in the urban habitat, to 1.56 ha in the suburban habitat and 1.60 ha in the peri-urban region, with a maximum range size of 6.61 ha. The median maximum distance reached from home was 99 m, and again varied with level of urbanisation (urban: 79 m; suburban: 141m; peri-urban: 148m; maximum 278 m). For home and core (50% KE) ranges, there were no significant differences with respect to study areas, cat sexes, cats living in the same household or day/night range. A decreased proportion of constructed surfaces (a proxy for urbanisation) was associated with an increase in cat range size. As urban areas grow, many areas containing species of conservation importance are encroached upon by residential zones on urban fringes. To protect these species we suggest that boundary habitats should be managed to reduce rates of cat access to these areas, or that buffer zones of 300–400mshould be formed between housing and areas containing vulnerable species. These management options may help mitigate the ecological consequences of cat predation.