Background: Loneliness is a growing public health concern, but little is known about how place affects loneliness, especially in adolescence. This is the first study to examine the influence of neighbourhoods on loneliness in early/middle adolescence. Methods: Baseline data from the #BeeWell cohort study in Greater Manchester (England) were used, with the sample comprising 36,141 adolescents (aged 12-15) across 1,590 neighbourhoods. These data were linked to neighbourhood characteristics using administrative data at the LSOA-level. Data were analysed using multilevel (individual, neighbourhood) regression models. Results: Neighbourhood explained 1.18% of the variation in loneliness. Moreover, ethnic, gender and sexual orientation inequalities in loneliness varied across neighbourhoods. Loneliness was higher in neighbourhoods with higher skills deprivation among children and young people, lower skills deprivation among adults, higher geographical barriers, lower outdoor environment deprivation, and higher population density. A longer distance from home to school was also associated with higher loneliness. More positive perceptions of the local area (feeling safe, trust in local people, feeling supported by local people, seeing neighbours as helpful, and the availability of good places to spend your free time) were associated with lower loneliness. Conclusions: Our findings suggest that local-level interventions may be particularly helpful to tackle adolescent loneliness.