BACKGROUND AND AIM: Urban greening may reduce loneliness by offering opportunities for solace, social reconnection, and supporting processes such as stress relief. We (i) assessed associations between residential green space and cumulative incidence of, and relief from, loneliness over four years; and (ii) explored contingencies by cohabitation status. METHODS: Multilevel logistic regressions of change in loneliness status in 8,049 city-dwellers between 2013 (baseline) and 2017 (follow-up). Associations with objectively-measured discrete green space (e.g. parks) buffers (400m, 800m and 1600m) were adjusted for age, sex, disability, cohabitation status, children and socioeconomic variables. Results were translated to absolute risk reductions in loneliness per 10% increase in urban greening. RESULTS:The absolute risk of loneliness rose from 15.9% to 16.9% over the four years; however, 10% increase in urban greening within 1600m was associated with lower cumulative incident loneliness (OR=0.927, 95%CI=0.862 to 0.996; absolute risk reduction=0.66%). Stronger association was observed for people living alone (OR=0.828, 95%CI=0.725 to 0.944). In comparison to people with 10% green space, odds ratios for cumulative incident loneliness were 0.833 (95%CI=0.695 to 0.997), 0.790 (95%CI=0.624 to 1.000) and 0.736 (95%CI=0.549 to 0.986) for 10-20%, 20-30%, and 30% green space, respectively. Compared to the 10% green space reference group with a 13.78% baseline risk of cumulative incident loneliness and 15.9% prevalent loneliness, associations translated to absolute risk reductions of 1.70%, 2.26% and 2.72% within populations at 10-20%, at 20-30%, and at 30% green space, respectively. These associations were stronger again for people living alone with 10-20% (OR=0.608, 95%CI=0.448 to 0.826), 20-30% (OR=0.649, 95%CI=0.436 to 0.966) and 30% (OR=0.480, 95%CI=0.278 to 0.829) green space within 1600m. No associations with green space within 400m or 800m, or relief from loneliness reported at baseline were observed. CONCLUSIONS:Lower cumulative incidence of loneliness was observed among people with more green space within 1600m of home, especially for people living alone. KEYWORDS: green space, environmental justice, mental health outcomes