This paper focuses on age diversity in neighbourhoods and its possible impacts on community wellbeing. The aims of this paper are (a) to investigate whether age diversity in neighbourhoods contribute to older residents’ wellbeing and (b) to explore older residents’ experiences and views on age diversity in their neighbourhood. These questions are addressed using a mixed-method approach combining survey and interview data and analysis. The data is derived from a survey (n = 420) and 19 semistructured interviews addressed to the older residents of a rental house company located in Eastern Finland. The interview data is analysed using qualitative content analysis. The results of qualitative data indicate that older adults see various benefits in an age-diverse living environment. In the quantitative analysis, we apply multilevel models in our statistical analyses to take both community- and individual-level variation into account. The quantitative results show that older adults living in age-diverse neighbourhoods reported higher community wellbeing. Such association was not found among the younger residents. Overall, our study adds to the understanding of the importance of neighbouring relations on community wellbeing in later life. The results can be utilized when developing age-friendly environments and housing policies at local and national levels.